High-voltage battery for a motor vehicle

Abstract

The invention relates to a high-voltage battery for a motor vehicle, comprising at least the following components: - at least one battery module; - a module housing in which at least one battery module is accommodated; and - at least one flow channel for guiding a temperature control fluid to regulate the temperature of at least one battery module housed in the module casing. The high-voltage battery is characterized primarily by the fact that at least one of the battery modules is directly fixed to the module casing by means of a material-bonded connection. The high-voltage battery proposed here allows for a reduction in mass and / or an increase in the stability of the high-voltage battery and / or a vehicle frame.

Description

[0001] The invention relates to a high-voltage battery for a motor vehicle, a method for manufacturing such a high-voltage battery, and a motor vehicle with such a high-voltage battery.

[0002] In the field of motor vehicles, for example passenger cars, (sometimes purely) electric drives are increasingly being used, which require high-voltage batteries. These high-voltage batteries must be maintained within a narrow temperature range during operation, charging, and when high power is required. The high-voltage battery must neither be overcooled nor overheated. Such a high-voltage battery, especially in so-called BEVs (Battery Electric Vehicles), comprises a large number of individual battery modules, each of which contains either a battery cell (usually with a single electrode and a single cathode) or a stack of a small number of battery cells. These battery modules must be maintained at a constant temperature, which often involves indirect or direct heat transfer to a liquid that is passed through a module housing.

[0003] Such a module housing must be integrated into the vehicle structure and represents a considerable additional mass, especially in BEVs. Therefore, the aim is to optimally reduce this mass.

[0004] Based on this, the present invention is based on the object of at least partially overcoming the disadvantages known from the prior art. The features of the invention are derived from the independent claims, for which advantageous embodiments are presented in the dependent claims. The features of the claims can be combined in any technically reasonable manner, whereby the explanations from the following description as well as features from the figures, which comprise additional embodiments of the invention, can also be consulted for this purpose.

[0005] The invention relates to a high-voltage battery for a motor vehicle, comprising at least the following components: - at least one battery module; - a module housing in which the at least one battery module is accommodated; and - at least one flow channel for conducting a tempering fluid for tempering the at least one battery module accommodated in the module housing.

[0006] The high-voltage battery is primarily characterized by the fact that at least one of the battery modules is fixed directly to the module housing by means of a material connection.

[0007] Unless explicitly stated otherwise, ordinal numbers used in the preceding and following descriptions serve only to clearly distinguish them and do not reflect the order or ranking of the designated components. An ordinal number greater than one does not necessarily imply that another such component must be present.

[0008] As described above, the high-voltage battery is suitable, for example, for a motor vehicle, preferably for supplying an electric drive motor with the required electrical voltage. In order to provide high performance of the electric drive motor and, at the same time, a long operating time (for example, in a BEV according to a WLTP driving cycle [WLTC] of 600 h [six hundred hours]), considerable charging capacities are required. This applies to both hybrid vehicles (with an additional internal combustion engine) and BEVs. At the same time, however, the performance requirements for an operating battery have increased even in a combustion-based motor vehicle, so that high-voltage batteries with considerable charging capacity and thus a not negligible mass are increasingly being used for such vehicles. However, the requirements to achieve a low overall mass have also increased significantly in conventional applications.

[0009] A battery module comprises a single battery cell or a stack of battery cells. The battery module includes a separate cell housing as a protective casing or is designed without such a cell housing, for example, consisting solely of a single battery cell or multiple battery cells, with each battery cell consisting of a single electrical storage functional unit with an electrode and a cathode.

[0010] Depending on the embodiment, the module housing is designed to accommodate a single battery module up to a plurality of battery modules. For this purpose, the module housing comprises, among other things, the electrical connections for electrically connecting the individual battery modules to one another (in series and / or parallel) and / or to a consumer. In one embodiment, the module housing additionally comprises a controller for protecting and / or operating the high-voltage battery within safe parameters, and preferably also in an operating mode that is optimal for a current power demand (e.g., high voltage for rapid acceleration or, conversely, efficient use of the chemically stored electrical charge for the longest possible operating time). In one embodiment, the temperature of the high-voltage battery is monitored or controlled, with a temperature being recorded either selectively or cell-specifically.In one embodiment, by means of the control of the high-voltage battery, an aging of the battery cells and / or the so-called dendrite formation is taken into account in the power consumption or power output, preferably reduced as much as possible in at least most power requests.

[0011] Furthermore, at least one flow channel is provided for a temperature control fluid, preferably a liquid, by means of which the battery modules can be temperature-controlled indirectly (i.e., with a partition wall or separation membrane) or directly (i.e., with direct contact with electrically conductive elements, at least in the event of a fault, without resulting in operational failure). A dielectric fluid, for example, is suitable for direct temperature control. The flow is controlled externally (e.g., via a circulation pump controlling the volume flow) or internally (e.g., by means of a control flap), with the control being supported by the control system of the high-voltage battery itself or being managed autonomously.

[0012] It should be noted that a particular flow channel is not necessarily designed like an enclosed conduit, but rather has a complex structure, for example, with the necessary infrastructure forming the walls or obstacles in the module housing. Taking these into account, the most efficient flow is designed, i.e., with low flow resistance but also with good heat transfer. This is achieved, among other things, by avoiding corners that form dead water zones or sharp constrictions with high flow resistance and high flow velocity.

[0013] Here, it is proposed that the battery modules themselves are directly connected to the module housing by means of a material-to-material connection. In one embodiment, or at some locations, an adhesive is used. In a preferred embodiment, a material-to-material connection is formed by welding. In a preferred embodiment, a battery module is connected to the module housing exclusively by means of a material-to-material connection. In a preferred embodiment, such a battery module, preferably all of the battery modules, is fixed within the module housing exclusively by means of the material-to-material connections. In a preferred embodiment, a battery module can be mounted or is mounted in a motor vehicle exclusively by means of the module housing, i.e. (at least apart from an electrical connection) it is not directly connected to a component of the motor vehicle.

[0014] In one embodiment, the module housing comprises a plastic material that can preferably be connected to a battery module by welding, with the plastic material particularly preferably being melted or partially melted. Alternatively or additionally, the integral connection, preferably a welded connection with the addition of a filler material, is formed without melting or partially melting the module housing.

[0015] In one embodiment, a respective battery module comprises an outer shell which can be melted or partially melted without causing thermal impairment to the storage unit. The outer shell is preferably made of a plastic. Alternatively or additionally, the outer shell is made of a metallic material and is spaced apart from the storage unit of the battery module or thermally insulated in such a way that thermal impairment to the storage unit when the metallic outer shell melts or partially melts can be sufficiently reliably excluded. Alternatively or additionally, the material-to-material connection, preferably a welded connection with or without the addition of a filler material, is formed without melting or partially melting the outer shell of the battery module.

[0016] In one embodiment, the module housing comprises a holder for a respective battery module, so that a battery module is easily pre-positioned in the module housing, at least for the duration of the connection process by means of the integral connection, preferably without additional aids. In one embodiment, at least a portion of a holder remains permanently, which supports the fixation of the respective battery module in addition to the integral connection. Alternatively, the holder is subsequently removed or completely or partially reshaped during the formation of the integral connection, wherein the respective material is preferably used to form the integral connection.

[0017] It is further proposed in an advantageous embodiment of the high-voltage battery that the material connection of the battery module in question with the module housing is formed by laser welding, wherein the weld seam forming a material connection is arranged exclusively on the inside of the module housing, wherein, preferably when the module housing is open, a line of sight to the weld seam is concealed, at least in part, by means of the at least one battery module.

[0018] Laser welding is characterized by high precision and high energy efficiency, as well as high production speed. It is therefore well suited to applying the required welding energy, i.e., heat, in a very localized manner. This means that the battery modules are not subjected to any or only a sufficiently low thermal load. It should be noted that this is also possible with other welding processes, but usually requires greater structural effort, for example, to interrupt heat conduction or to maintain a sufficiently large distance from the weld seam to be formed. A material-to-material bond using laser welding is therefore advantageous not only in terms of structure and mass, but also in terms of stability over the desired service life, especially compared to an adhesive bond, but also compared to other welding processes or (hard or soft) soldering.

[0019] In an advantageous embodiment, a seal or a sealing definition of a flow direction in an adjacent flow channel is formed by means of a weld seam.

[0020] In an advantageous embodiment, a structural element for load bearing or uninterrupted load transmission is set up by means of the weld seam.

[0021] Furthermore, it is proposed here (in a preferred embodiment) that the weld seam be arranged exclusively on the inside, i.e. within the module housing, for example in the region of one of the flow channels (for example adjacent to a flow channel). This can be implemented particularly easily using laser welding, but also using an adhesive connection and (hard or soft) soldering. By arranging the weld seams on the inside of the module housing, an embodiment of the module housing can be implemented particularly easily which forms a tight wall for the temperature control fluid, i.e. an embodiment in which, preferably at least on the module housing side, no separate conduit structure is formed, but rather direct contact with the temperature control fluid.

[0022] In an advantageous embodiment, access to the weld seam to be formed is restricted during the manufacturing process, concealed up to a line of sight. For example, the at least one battery module is packaged so tightly in the module housing that accessibility is limited. When the module housing is still open (but still blind with respect to the at least one weld seam) or when the module housing is already completely closed (at least pre-assembled), the welding energy is then applied from outside the module housing to the relevant area (fixing section) of the module housing and the relevant battery module, preferably through the wall of the module housing.Laser welding is particularly preferably used for this purpose, in which the welding energy is applied in a defined manner to the relevant area to form the desired weld seam by focusing the at least one laser beam and / or by selecting the material (for example a plastic that is transparent to the laser light).

[0023] It is further proposed in an advantageous embodiment of the high-voltage battery that at least one of the flow channels has at least one channel section with a flow extension, which is arranged directly adjacent to one of the battery modules, wherein the channel section is preferably enclosed exclusively by one of the battery modules and the module housing.

[0024] The module housing comprises one or more flow channels. For efficient temperature control of the battery modules, the closest possible contact with the temperature control fluid is desirable. Therefore, it is proposed that at least one (preferably all) of the flow channels be in direct contact with the battery module(s). The flow path is aligned, for example, along a row of battery modules, from a flow inlet into the module housing to a flow outlet (reversibility of the flow direction is not excluded).It should be noted that the flow in the flow channel or its orientation may be complex under certain circumstances, for example, in a directly adjacent arrangement to one or more cylindrical and / or prismatic battery modules, but also due to structural elements of the module housing itself or concessions to internal and / or external installation space conditions. The flow extension is therefore to be understood as an extension along an averaged flow direction (in a main state or maximum volume flow rate of the temperature control fluid) and / or along a simplified representation of a flow line without consideration of, for example, undercuts and branches.

[0025] In an advantageous embodiment, such a channel section is not separately enclosed. Rather, this channel section is defined exclusively as a result of the installed components, preferably the entire flow channel, and the channel section is in direct contact with a respective battery module and otherwise (preferably exclusively) with the module housing. It should be noted that in one embodiment, a weld seam is regarded as part of the module housing or the battery module in question. Alternatively, the weld seam itself is not in contact with the temperature control fluid or is in direct contact with the temperature control fluid at most via a gap without any significant flow velocity. In one embodiment, a seal formed integrally from the module housing or separately is provided between the battery module in question and the module housing at the channel section.In one embodiment, a structural component of the high-voltage battery or the module housing is also provided.

[0026] It should be noted that in an embodiment with a plurality of battery modules, a corresponding plurality (e.g., an identical number) of channel sections are connected to form a flow channel. In an embodiment with a free spacing between at least two of the battery modules, a branch to the flow channel is then formed, or this free spacing is provided with the aid of at least one guide element for redirecting the flow path for particularly close heat exchange contact with the respective battery modules, as well as simultaneously ensuring a gentle and thus low-flow-resistance passage of the temperature control fluid through the module housing.

[0027] It should be noted that one or more flow channels are provided in the module housing. In one embodiment, several flow channels are structurally separated from one another, possibly with reduced or even (technically sufficiently) prevented heat exchange between them. In one embodiment, the separation is a conceptual separation or, in the flow pattern, partially (e.g., repeatedly) separated from one another due to (e.g., recurring) separations (e.g., in the channel sections in contact with an associated battery module), whereby an exchange between the individual flow channels is possible or even enforced by means of a corresponding guide element.

[0028] It is further proposed in an advantageous embodiment of the high-voltage battery that the module housing has at least one bulge between two fixing sections, wherein at least one of the channel sections is formed in the bulge, and wherein at least one of the battery modules is connected to each of the two fixing sections, wherein the material connection to the battery module is preferably formed on at least one of the fixing sections.

[0029] Because the module housing has a bulge, a flow-through volume is formed between the two fixing sections for securing one or more battery modules each. Preferably, at least one of the bulges is a ribbing of the module housing aligned in the flow direction, preferably as a structure that is visible from the outside due to an (at least approximately) constant wall thickness, particularly preferably as a load-bearing or stiffening structural element of the module housing. Alternatively or additionally, the position of one of the battery modules in the module housing defines the shape of a bulge, so that the channel section of a flow channel is formed between the respective battery module and the inside of the bulge.

[0030] By means of the two fixing sections on the sides of the bulge, the bulge itself is stiffened in interaction with the respective battery module (e.g. purely against tension) or conversely (or against a different load direction, e.g. compressive load) the battery module is stabilized by means of the stiffer bulge.

[0031] In one embodiment, a plurality of protrusions are provided, wherein the fixing sections, viewed from the outside, are recognizable as indentations. In one embodiment, each fixing section is a (for example, punctiform and / or circular) depression in an otherwise at least externally flat outer surface of the module housing.

[0032] In an advantageous embodiment, such a material-to-material connection as described above is formed on at least one (preferably all) of the fixing sections. In one embodiment, an enclosed channel section is formed in a recess forming the wall of the module housing and a battery module fixed to the module housing by means of the material-to-material connection by means of the associated two fixing sections.

[0033] In an advantageous embodiment of the high-voltage battery, it is further proposed that the battery module has a cell housing. Preferably, the at least one battery module is more rigid than the module housing itself, in at least one common load direction in the assembled position.

[0034] In one embodiment, the battery module is designed without a cell housing and is therefore a sensitive component that can only absorb a tensile load. For example, such a housingless battery module is stabilized by the module housing, for example, by means of the two or more associated fixing sections of the module housing according to the previous description.

[0035] In another embodiment, the battery module is designed with a cell housing. Such a cell housing is usually designed to protect the internal (encapsulated) battery cell(s) and has sufficient mechanical rigidity to protect the battery cell(s) against impact, pressure, or bending loads far exceeding the force exerted by human handling during assembly. The cell housing thus already has a stability that makes it usable as a structural component for load-bearing. However, due to application requirements (particularly in a motor vehicle), a single battery module cannot be used as a high-voltage battery without a module housing.

[0036] It is proposed here that these components, which are redundant in terms of their stability in a conventional design, be utilized for the desired overall stability of the high-voltage battery by means of the integral connection directly between the battery module (or its cell housing) and the module housing. Compared to a conventionally designed high-voltage battery with a non-direct (integral) connection between the at least one battery module and the module housing, one embodiment achieves an increase in the stability of the high-voltage battery, and one embodiment (alternatively or additionally) achieves a reduction in mass.

[0037] In an advantageous embodiment, by utilizing the stability of the cell housing, a module housing can be designed to be softer than the battery module (for example, the cell housing alone), whereby the module housing particularly preferably only achieves its desired stability through the installation and fixing of the at least one battery module. In one embodiment, the module housing is merely a soft shell that enables positioning of the at least one battery module, the at least one flow channel, and / or other components (for example, control system, electrical connections, sensors) relative to one another and / or relative to the installation situation (for example, in a motor vehicle).

[0038] For example, the module housing is designed to be just sufficiently stable to ensure safe transport and / or movement during assembly. For example, the module housing is designed to be just sufficiently stable to sufficiently rule out the leakage of temperature control fluid during operation over a desired service life, wherein, for example, in an installation situation in the underbody, a separate underbody protection or one formed integrally with the module housing is preferably provided. For example, the high-voltage battery is only stabilized for the desired application through installation (for example in a motor vehicle), wherein the at least one battery module is connected to the adjacent structure of the installation situation by means of the module housing. The module housing plays no or a subordinate role in stabilizing the high-voltage battery.

[0039] It should be noted that the stiffness depends on the load direction of an assumed load case. In one embodiment, the stiffness in one load direction of the module housing is higher (alone) than that of the battery module and at the same time lower in another load direction. For example, the battery module has a width extension (for example with at least one prismatic battery cell) and / or height extension (for example with at least one round cell), and in this extension direction the battery module is stiffer than in the corresponding direction according to the mounted position in the module housing. Transverse to this direction, for example, the module housing is stiffer than the battery module. Alternatively or additionally, a desired stiffness in a load direction is only created in the mounted state in the connection between the at least one battery module and the module housing.

[0040] It should be noted that in an application, several high-voltage batteries are provided, of which at least one is designed as described here. In this case, a common high-voltage battery is preferably formed functionally, i.e., by means of an electrical connection and / or common control of these individual high-voltage batteries, which, however, in an advantageous embodiment are separately housed in their own module housings. Alternatively, several sub-module housings are only connected to one another in the installed situation to form a common module housing and, if appropriate, only then are they closed off from the environment in such a way that the at least one flow channel is formed or protected in the desired manner.

[0041] According to one embodiment, a high-voltage battery is thus proposed in which the at least one battery module is connected to the module housing in such a way that the cell housing itself is also structurally utilized. For this purpose, the at least one battery module is installed in the module housing, and there are defined contact surfaces (for example the fixing sections) between the module housing and the at least one battery module. There are also defined distances between the module housing and each of the battery modules, preferably formed by one or more bulges. The distances are required to cool the battery module over as full a surface as possible in the case of a high-voltage battery with direct cooling, and in the case of venting, so that hot gas can be discharged in a defined manner.

[0042] The contact surfaces between the module housing and the battery module are used to connect the battery module in question to the housing after it has been installed therein. In one embodiment, for example, the material of the module housing is selected such that a laser passes through this material and directly onto the cell housing, heating it locally. By heating the cell housing at this contact point with the module housing, the material of the module housing (but preferably not the cell housing) on ​​the contact surface is briefly melted or molten. This molten or molten area then forms a structural (material-locking) connection with the cell housing. By means of this local connection of the battery module to the module housing, significant forces can be transmitted. The cell housing is thus integrated to absorb and transmit significant forces.In one embodiment, the module housing is thus relieved of load and can therefore be designed to be thinner (and thus lighter).

[0043] According to one embodiment, this enables the at least one battery module to be sufficiently firmly fixed in the module housing without the additional installation of a so-called cell holder plate or similar device, on which the battery modules or battery cells are first pre-assembled into cell packs, in order to then assemble these, together with the cell holder plate, in the module housing. Instead, if necessary, a positioning tool for forming or pre-assembling cell packs can be used, which is not installed in the module housing. The module housing can therefore be designed without a cell holder plate.

[0044] In an advantageous embodiment, this local, integral connection allows the respective battery module to be inserted, for example, as a tension strut in the module housing. This at least one tension strut is required, for example, to prevent unwanted bulging of the module housing, which would occur, for example, in a high-voltage battery with direct cooling due to the internal pressure of the flowing temperature control fluid.

[0045] According to a further aspect, a method for manufacturing a high-voltage battery is proposed, the method comprising at least the following steps in the order mentioned: a. Providing the module housing and at least one battery module; b. Inserting at least one of the battery modules into the module housing; and c. Fixing the battery module directly to the module housing by means of a material-to-material connection.

[0046] The high-voltage battery to be manufactured using this method is designed at least functionally according to the introduction of an embodiment according to the preceding description. Preferably, at least one flow channel for a temperature control fluid for controlling the temperature of the at least one battery module is included. Such a flow channel is preferably formed without any further (separate) conduit wall, but particularly preferably exclusively by means of the at least one battery module and the module housing. With the method proposed here for manufacturing the high-voltage battery, at least the aforementioned advantages are achieved (in the respective embodiment). Furthermore, the method proposed here proposes rapid and cost-effective production of a high-voltage battery.Irrespective of this, a simple and stable high-voltage battery can be manufactured without the need for special production of battery modules, i.e. with (large-scale) series components up to mass parts, and / or with battery modules that can be easily and safely transported.

[0047] In step a, preparatory steps may have already been performed, and additional components may have been provided or (pre-)assembled. Reference is made to the previous description of the high-voltage battery, at least analogously.

[0048] In step b, the respective battery module is inserted into the module housing, for example, pre-assembled. This requires a separate holder and / or a corresponding shape or receptacle is created in the module housing. The at least one battery module is (apart from tolerated or planned deformations or displacements) in the position in which the respective battery module is to be arranged in the final state of the high-voltage battery (at least before its installation in an application, for example, in a motor vehicle), i.e., (at least pre-)assembled in the target position.

[0049] In step c., the inserted battery module is connected directly (i.e. without intermediate elements) to the module housing by means of a material-to-material connection, i.e., fixed to it.

[0050] It should be noted that in one embodiment, in a material-to-material bond using an adhesive, step b. and step c. (or preparatory steps for step c.) are carried out simultaneously or at an overlapping time. In one embodiment, an adhesive is first activated by heating or (for example, UV) irradiation. Alternatively or additionally, an adhesive is applied before step b. and cures after or during step b.

[0051] In the case of a material-to-material connection for step c. by means of (hard or soft) soldering or welding with a filler metal, the material to be melted or fused (solder or filler metal) is applied before or after step b.

[0052] In the case of a purely thermally generated material connection, the tool for generating the necessary energy is preferably used only in step c.

[0053] It is further proposed in an advantageous embodiment of the method that in step b. the at least one battery module is inserted by means of a positioning tool, whereby the positioning tool is removed before or after step c.

[0054] In one embodiment, the at least one battery module, preferably a plurality of battery modules, is inserted into the module housing by means of a positioning tool. The positioning tool pre-positions the battery module relative to the module housing and / or to the other components (e.g., the other battery modules) of the high-voltage battery. For example, the positioning tool is configured such that the at least one battery module (and optionally other components of the high-voltage battery) can be pre-assembled easily and quickly, for example, in an automated manner. For example, the positioning tool comprises support elements by means of which the positioning tool, together with the pre-positioned components, can be transported easily and safely and / or aligned relative to the module housing for inserting the at least one battery module.

[0055] For example, the positioning tool is functionally similar to a cell holder plate conventionally installed in a module housing, except that, on the contrary, the positioning tool is not installed, but is removed again after insertion according to step b. or before or after fixing according to step c., in any case before closing the module housing (preferably before sub-step b2. according to the following description).

[0056] It is further proposed in an advantageous embodiment of the method that the module housing comprises a first housing part and a second housing part, wherein in a sub-step a1. the first housing part is provided and in a sub-step b1. the at least one battery module is inserted into the first housing part, wherein in a sub-step a2, the second housing part is joined to the first housing part, whereby at the same time in a sub-step b2, the at least one battery module is inserted into the second housing part, wherein preferably in a sub-step c1. before sub-step a2. the at least one battery module is fixed to the first housing part by means of a material connection, and / or wherein preferably in a sub-step c2 after sub-step b2 the at least one battery module is fixed to the second housing part by means of a material connection.

[0057] In one embodiment, a first half-shell and a second half-shell are formed. In one embodiment, the half-shells are of the same type on the inside, for example on the inside or are identical overall. In one embodiment, more than two housing parts are provided. In one embodiment, exclusively one or exclusively two of the housing parts are designed to receive or insert according to step b. of the at least one battery module. In one embodiment, exclusively one or exclusively two of the housing parts are designed to fix according to step c. of the at least one battery module. In one embodiment, at least one of the housing parts is designed in multiple parts, but preferably in one part.

[0058] In this method, the at least one battery module (for example, a plurality of battery modules pre-positioned using a positioning tool) and a first housing part (for example, a first half-shell and / or optionally further housing parts) are provided (substep a1.). Subsequently, the at least one battery module is inserted into this provided first housing part (substep b1.). In an advantageous embodiment, at least one, preferably all, of the battery modules are then fixed to the first housing part by means of a material-to-material connection (substep c1.).

[0059] It should be noted that in one embodiment, each battery module is fixed to only one of the housing parts by means of a material-to-material connection to avoid static overdetermination. Preferably, a battery module is fixed (directly) to two (opposite) housing parts by means of a material-to-material connection to achieve high stability of the high-voltage battery. If appropriate, the battery module and / or at least one of the housing parts is designed to be sufficiently elastically or plastically deformable for this purpose and / or exhibits a comparable (i.e., irrelevant to the intended use or negligibly different) thermally induced expansion.

[0060] A second housing part (for example a second half-shell and / or optionally further housing parts) is then provided for this method (sub-step a2.). Subsequently (sub-step b2.) the at least one battery module is inserted into this provided second housing part. The positioning tool, if used, has preferably already been removed (for example immediately after sub-step b1. or sub-step c1.). In one embodiment, at least one, preferably all, of the battery modules are then fixed to the second housing part by means of a material-to-material connection in the subsequent step (sub-step c2.). Alternatively, sub-step c1. or sub-step c2. does not take place at all or only takes place for one group of battery modules. In one embodiment, step c. (i.e. sub-step c1. and / or sub-step c2.) finally takes place after closing or with the closing or fixing of a locking connection of the housing parts, preferably as explained in more detail below.

[0061] According to a further aspect, a motor vehicle is proposed, comprising a vehicle frame, a propulsion device and a drive train with a drive motor and a high-voltage battery according to an embodiment according to the above description, preferably for supplying the electrically designed drive motor, wherein, for propelling the motor vehicle, the drive engine is connected to the propulsion device via the drive train in a torque-transmitting manner, wherein the high-voltage battery is preferably manufactured by means of a method according to an embodiment according to the above description.

[0062] The motor vehicle has, for example, as described above, a hybrid drive with an electric drive motor and a An internal combustion engine or exclusively an electric drive motor for propelling the motor vehicle. Alternatively, an internal combustion engine alone is provided. The high-voltage battery is designed to supply a high-performance, electrically powered component of the motor vehicle. Such a high-performance component is, for example, a starter motor for an internal combustion engine, an air conditioning compressor for an air conditioning system and / or for a cooling circuit for power components of the motor vehicle, and / or alternatively, an electric drive motor for propelling the motor vehicle.

[0063] The motor vehicle is, for example, a passenger car, a truck or another commercial vehicle (e.g. a bus or snow plow).

[0064] The vehicle frame is the structural component or structural assembly of the motor vehicle, to which the remaining components of the motor vehicle are directly or indirectly connected, for example, in a conventional manner. The propulsion system is, for example, one or more wheel axles with (each) at least two drive wheels that can be supplied with torque (preferably via a differential as needed). The wheels of the motor vehicle (and thus also the drive wheels of the propulsion system) are connected to the vehicle frame, preferably via a damping wheel suspension.

[0065] The drive train is designed to generate or provide, as needed, a torque for propelling the motor vehicle. For this purpose, at least one drive motor is provided as a torque source (as already indicated above). In one embodiment, a drive motor is provided for each drive wheel or each (drive) wheel axle. In one embodiment, a single drive motor is provided. In one embodiment, a drive motor is only an indirect torque source for propelling the motor vehicle, for example, in a so-called range extender.

[0066] The high-voltage battery is designed as described above. The high-voltage battery is mounted in the vehicle frame and connected to the at least one electrically operated high-performance component of the motor vehicle for delivering a power current. The delivery of stored electrical voltage is preferably controllable by means of a controller on board the motor vehicle.

[0067] The high-voltage battery proposed here enables a particularly lightweight construction of the motor vehicle, as at least one cell housing and / or a self-supporting structure of the module housing can be dispensed with.

[0068] It is further proposed in an advantageous embodiment of the motor vehicle that the high-voltage battery is mounted as a load-bearing, particularly preferably crash-load-bearing, structural component of the vehicle frame.

[0069] In addition to the aforementioned advantages, the high-voltage battery is designed in such a way that it itself forms a stiffening component of the vehicle frame, thus making the vehicle frame lighter. This has a twofold effect because the vehicle frame no longer has to form a supporting frame for the high-voltage battery (as is conventionally the case), but is also stiffened by the installed high-voltage battery. It should be noted again that the high-voltage battery itself is already lighter to construct, so this is not an alternative to using the high-voltage battery as a load-bearing structural component of the vehicle frame.

[0070] In a preferred embodiment, the high-voltage battery is mounted and designed such that it is mounted in the vehicle frame to absorb crash loads. Currently, attempts are being made to protect the high-voltage battery from crash loads, and for this purpose the vehicle frame or the mount for the (conventional) high-voltage battery is designed to be particularly rigid. The design of the module housing, namely the elimination of structural components within the module housing by utilizing the rigidity of the at least one cell housing and / or by saving mass by omitting a cell housing but maintaining a direct material connection between the at least one battery module, makes it possible for the high-voltage battery to comprise a structure that absorbs crash energy.It is possible that at least one battery module and / or the material connection (or its damage or destruction) is used as a measure to absorb crash energy.

[0071] The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, whereby it should be noted that the drawings are not to scale and are not suitable for defining proportions. It is shown in Fig. 1: a high-voltage battery with a plurality of battery modules in a first embodiment; Fig. 2: a high-voltage battery with a plurality of battery modules in a second embodiment; Fig. 3: a motor vehicle with a high-voltage battery; and Fig. 4: Process for manufacturing a high-voltage battery.

[0072] In Fig. 1 shows a high-voltage battery 1 with a plurality of battery modules 3 in a first exemplary embodiment in a schematic side view. Each battery module 3 comprises a single battery cell or a stack of battery cells. In this exemplary embodiment, the battery module 3 comprises its own cell housing 11 as a protective housing, for example, consisting solely of a single or multiple battery cells, wherein each battery cell consists of a single electrical storage functional unit with an electrode and a cathode. In this first exemplary embodiment, the battery cells are designed as round cells.

[0073] The cell housings 11 are arranged in a module housing 4, wherein the module housing 4 in the embodiment shown is designed to accommodate a plurality of battery modules 3 (here three). The module housing 4 comprises, among other things, the electrical connections (not shown here) for electrically connecting the individual battery modules 3 to one another (in series and / or parallel) and / or to a consumer. The module housing 4 comprises a plurality of bulges 9, in each of which a channel section 8 is formed, the flow extent of which is aligned (approximately) perpendicular to the image plane. Here, only one of the bulges 9 and one channel section 8 is designated pars-pro-toto.

[0074] The bulges 9 are here (purely optional) each arranged between two fixing sections 10. Here, at least one of the bulges 9 is designed as a ribbing of the module housing 4 aligned in the flow direction, preferably as a result of an (at least approximately) constant wall thickness with a structure that can be seen from the outside here (purely optional), particularly preferably as a load-bearing or stiffening structural element of the module housing 4. In addition, the position of one of the battery modules 3 in the module housing 4 defines the shape of a bulge 9, so that the said channel section 8 of a flow channel 5 with a suitable hydraulic cross-section is formed between the respective battery module 3 and the inside of the bulge 9.

[0075] For example, the temperature of the high-voltage battery 1 is monitored or controlled, with a temperature being detected at a specific point or cell-specifically. For temperature control, gaps are provided between the battery modules 3, which are configured as separate flow channels 5 or a common (here branched) flow channel 5 for a temperature control fluid. By means of the temperature control fluid, preferably a (particularly preferably dielectric) liquid, the battery modules 3 can be temperature-controlled indirectly (i.e., with a partition wall or separating membrane) or directly (i.e., with direct contact with electrically conductive elements, at least in the event of a fault, without resulting in operational failure).

[0076] It should be noted that a respective flow channel 5 is not necessarily designed in the manner of an enclosed conduit, but rather has, for example, a complex structure, with the necessary infrastructure in the module housing 4 forming the walls or obstacles, and taking these into account, the most efficient flow possible, i.e., with low flow resistance but also with good heat transfer, is formed. The channel sections 8 represent a component of this complex structure in this exemplary embodiment.

[0077] The battery modules 3 themselves are directly connected to the module housing 4 by means of a material-to-material connection 6. In this exemplary embodiment, the material-to-material connection 6 is formed by laser welding as a weld seam 7 on the fixing sections 10. In this exemplary embodiment, the weld seam 7 forms a seal or a sealing definition of a flow direction in the adjacent flow channel 5. In addition, the weld seam 7 forms a structural element for load absorption or uninterrupted load conduction along the load direction 12.

[0078] The weld seam 7 is arranged exclusively on the inside, i.e., within the module housing 4, for example, in the region of one of the flow channels 5 (for example, adjacent to a flow channel 5), on the fixing sections 10. By means of the two fixing sections 10 on the sides of the bulge 9, the bulge 9 itself is stiffened in interaction with the respective battery module 3 (for example, purely against tension) or, conversely (or against another load direction 12, for example, compressive load), the battery module 3 is stabilized by means of the stiffer bulge 9.

[0079] In Fig. 2 shows a high-voltage battery 1 with a plurality of battery modules 3 in a second exemplary embodiment in a schematic side view. The high-voltage battery 1 is, without exclusion of the general public, largely identical to the Fig. 1, and in this respect reference is made to the description therein and only the differences are discussed here.

[0080] In this second exemplary embodiment, the battery modules 3 or the battery cells accommodated therein (and optionally housed) are designed as prismatic cells, wherein here the battery modules 3 are preferably without cell housing 11 and preferably the battery modules 3 are each a single battery cell (i.e. chemical storage unit).

[0081] Independently of this, the battery modules 3 are also fixed to the module housing 4 at fixing sections 10, which are arranged between protrusions 9 of the module housing 4 by means of integral connections 6, for example, in the form of weld seams 7. A dashed line (here shown horizontally and broken) schematically indicates a positioning tool 13, by means of which the battery modules 3 are pre-positioned in the module housing 4, either as a whole or individually in (for example, cell) packs. For example, the battery modules 3 can be inserted into a pocket-shaped module housing 4 using the positioning tool 13, or inserted in a pre-positioned position into a housing part 14. The positioning tool 13 is removed again before or after the battery modules 3 are fixed.Due to the fixation of the battery modules 3, predetermined flow channels 5 or their channel sections 8 are arranged between the battery modules 3 and within the bulges 9.

[0082] In this exemplary embodiment, the (purely optional) module housing 4 comprises a first housing part 14 (as shown below) and a second housing part 15 (as shown above), which are joined to one another, for example welded to one another, in the plane of the positioning tool 13.

[0083] Furthermore, for the first and second exemplary embodiments, due to the fixation of the battery modules 3 to the module housing 4, an increase in rigidity along the load direction 12 of the high-voltage battery 1 can be achieved compared to conventional high-voltage batteries 1, for a desired overall stability of the high-voltage battery 1. Compared to a conventionally designed high-voltage battery 1 with a non-direct (material-bonded) connection 6 between the battery modules 3 and the module housing 4, an increase in the stability of the high-voltage battery 1 and (alternatively or additionally) a reduction in mass are achieved in this exemplary embodiment.Alternatively or additionally, the mass can be significantly reduced compared to a conventionally designed high-voltage battery 1, for example by stabilizing the module housing 4 for loads during use (for example solely for careful transport or for crash loading in the motor vehicle 2) and / or against a necessary internal pressure of the temperature control fluid only by inserting and fixing the battery modules 3.

[0084] In Fig. 3 shows a schematic plan view of a motor vehicle 2 with a high-voltage battery 1. The motor vehicle 2 has an electric drive motor 19 for propelling the motor vehicle 2. The high-voltage battery 1 is designed to supply power to a high-performance, electrically driven component of the motor vehicle 2 (in this case, at least the electric drive motor 19). The motor vehicle 2 further comprises a vehicle frame 16, from which the structural component or structural assembly of the motor vehicle 2 is formed. The remaining components of the motor vehicle 2 are directly or indirectly connected to the vehicle frame 16, for example in a conventional manner. The propulsion device 17 comprises a wheel axle 23 (here, for example, a single rear one) with drive wheels 20, 21 (here, two, purely optionally via a differential 22 as needed) that can be supplied with torque.The wheels of the motor vehicle 2 (and thus also the drive wheels 20, 21 of the propulsion device 17) are connected to the vehicle frame 16, preferably via a damping wheel suspension.

[0085] The drive train 18 is configured to generate or provide, as needed, a torque for propelling the motor vehicle 2. The high-voltage battery 1 is mounted in the vehicle frame 16 and connected to the at least one electrically operated, high-performance component of the motor vehicle 2 for delivering a power current. The delivery of stored electrical voltage is preferably controllable by means of a controller on board the motor vehicle 2. Preferably, the high-voltage battery 1 is a component that stabilizes the vehicle frame 16, i.e., a structural component of the motor vehicle 2, and is not merely mounted in the vehicle frame 16 as its additional load requirement.

[0086] In Fig. 4 shows a method for manufacturing a high-voltage battery 1 in a flow chart. The following description refers to the high-voltage battery 1 in Fig. 1 and Fig. 2, in this respect reference is made to the description there.

[0087] In step a. (here sub-step a1.), the module housing 4 (or here a first housing part 14 of the module housing 4) and the at least one battery module 3 are provided. Furthermore, preparatory steps may already have been performed, and further components may have been provided (for example, according to sub-step a2.) or (pre-)assembled. In step a. (or sub-step a1.), the at least one battery module 3 (for example, a plurality of battery modules 3 pre-positioned by means of a positioning tool 13) and the first housing part 14 (for example, a first half-shell and / or, if applicable, further housing parts) are also provided.

[0088] In step b. (here sub-step b1.), the at least one battery module 3 is inserted, for example pre-assembled, into the module housing 4 or into the first housing part 14. A separate holder (for example, by means of a positioning tool 13 that can be removed again) is required and / or a corresponding shape or receptacle is created in the module housing 4. The at least one battery module 3 is (apart from tolerated or planned deformations or displacements) in the position in which the respective battery module 3 is to be arranged in the final state of the high-voltage battery 1 (at least prior to its installation in an application, for example in a motor vehicle 2), i.e. (at least pre-)assembled in the target position.

[0089] In sub-step a2 (here purely optionally after sub-step b1), a second housing part 15 (for example, a second half-shell and / or optionally additional housing parts) is provided. Before, at the same time, and / or after this (but before sub-step c1), in sub-step b2, the at least one battery module 3 is inserted into this provided second housing part 15. The positioning tool 13, if used, has preferably already been removed (for example, immediately after sub-step b1).

[0090] Subsequently, in step c. (here purely optionally in a sub-step c1.), at least one, preferably all, of the battery modules 3 are fixed to the first housing part 14 by means of a material-to-material connection 6. Finally or alternatively, in a sub-step c2., at least one, preferably all, of the battery modules 3 are fixed to the second housing part 15 by means of a material-to-material connection 6. Alternatively, sub-step c1. or sub-step c2. does not take place at all or only takes place for one group of battery modules 3. In one embodiment, sub-step c1. and / or sub-step c2. takes place finally after the closing or with the closing or fixing of a closing connection of the housing parts 14, 15.

[0091] With the high-voltage battery proposed here, a saving in mass and / or an increase in stability of the high-voltage battery and / or a vehicle frame can be achieved. List of reference symbols 1 high-voltage battery 2 motor vehicles 3 Battery module 4 module housings 5 flow channel 6 material connection 7 Weld seam 8 Canal section 9 bulge 10 fixing sections 11 Cell housing 12 Load direction 13 Positioning tool 14 first housing part 15 second housing part 16 vehicle frames 17 Propulsion equipment 18 Powertrain 19 Drive machine 20 right drive wheel 21 left drive wheel 22 Differential 23 Wheel axle

Claims

[1] High-voltage battery (1) for a motor vehicle (2), comprising at least the following components: - at least one battery module (3); - a module housing (4) in which the at least one battery module (3) is accommodated; and - at least one flow channel (5) for conducting a tempering fluid for tempering the at least one battery module (3) accommodated in the module housing (4), characterized by that at least one of the battery modules (3) is fixed directly to the module housing (4) by means of a material connection (6). [2] High-voltage battery (1) according to claim 1, wherein the material connection (6) of the respective battery module (3) with the module housing (4) is formed by laser welding, wherein the weld seam (7) forming a material connection (6) is arranged exclusively on the inside of the module housing (4), wherein, preferably when the module housing (4) is open, a line of sight to the weld seam (7) is concealed, at least in part, by means of the at least one battery module (3). [3] High-voltage battery (1) according to claim 1 or claim 2, wherein at least one of the flow channels (5) has at least one channel section (8) with a flow extension, which is arranged directly adjacent to one of the battery modules (3), wherein the channel section (8) is preferably enclosed exclusively by one of the battery modules (3) and the module housing (4). [4] High-voltage battery (1) according to claim 3, wherein the module housing (4) has at least one bulge (9) between two fixing sections (10), wherein at least one of the channel sections (8) is formed in the bulge (9), and wherein at least one of the battery modules (3) is connected to each of the two fixing sections (10), wherein the material connection (6) to the battery module (3) is preferably formed on at least one of the fixing sections (10). [5] High-voltage battery (1) according to one of the preceding claims, wherein the battery module (3) has a cell housing (11). Preferably, the at least one battery module (3) is more rigid than the module housing (4) in at least one common load direction (12) in the assembled position. [6] Method for manufacturing a high-voltage battery (1), the method comprising at least the following steps in the order mentioned: a. Providing the module housing (4) and at least one battery module (3); b. Inserting at least one of the battery modules (3) into the module housing (4); and c. Fixing the battery module (3) directly to the module housing (4) by means of a material connection (6). [7] Method according to claim 6, wherein in step b. the at least one battery module (3) is inserted by means of a positioning tool (13), wherein the positioning tool (13) is removed again before or after step c. [8] A method according to claim 6 or claim 7, wherein the module housing (4) comprises a first housing part (14) and a second housing part (15), wherein in a sub-step a1. the first housing part (14) is provided and in a sub-step b1. the at least one battery module (3) is inserted into the first housing part (14), wherein in a sub-step a2, the second housing part (15) is joined to the first housing part (14), whereby at the same time in a sub-step b2, the at least one battery module (3) is inserted into the second housing part (15), wherein preferably in a sub-step c1. before sub-step a2. the at least one battery module (3) is fixed to the first housing part (14) by means of a material connection (6), and / or wherein preferably in a sub-step c2 after sub-step b2 the at least one battery module (3) is fixed to the second housing part (15) by means of a material connection (6). [9] Motor vehicle (2), comprising a vehicle frame (16), a propulsion device (17) and a drive train (18) with a drive machine (19) and a high-voltage battery (1) according to one of Claim 1 to Claim 5, preferably for supplying the electrically operated drive machine (19), wherein for propelling the motor vehicle (2), the drive machine (19) is connected to the propulsion device (17) via the drive train (18) in a torque-transmitting manner, wherein the high-voltage battery (1) is preferably manufactured by means of a method according to one of claims 6 to 8. [10] Motor vehicle (2) according to claim 9, wherein the high-voltage battery (1) is mounted as a load-bearing, particularly preferably crash-load-bearing, structural component of the vehicle frame (16).

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