Battery housing for a battery module of a traction battery of a motor vehicle

Abstract

Battery housing (10) for a battery module of a traction battery of a motor vehicle, comprising a housing (12) for enclosing at least one battery cell of the battery module, at least one cooling groove (18) provided in at least one housing wall (16) of the housing (12) and opening away from the battery cell for the passage of a cooling fluid, and a cover (20) designed as a flat plate and connected to the housing wall (16) for closing the at least one cooling groove (18), characterized in that the cover (20) has a centering opening (22) that can be placed on a centering body (24) of the housing wall (16).

Description

The invention relates to a battery housing with the aid of which a battery module of a traction battery of a motor vehicle can be housed and tempered.DE 10 2017 104 710 A1 discloses a battery housing for a battery module of a traction battery of a motor vehicle, wherein the battery housing has a depression, into which a profiled additional component is inserted in order to form cooling channels between the additional component and a flat base of the depression.DE 20 2018 101 387 U1 discloses a battery housing for a traction battery of a motor vehicle, in which coolant channels attached to a thermal plate can be inserted into corresponding grooves on the outer side of the battery housing.DE 10 2012 012 663 A1 discloses a battery housing for battery cells, in which a separating body is provided between the battery cells and an underside of a trough accommodating the battery cells, wherein cooling channels are formed between the separating body and the underside of the trough.WO 2018 / 104505 A1 discloses a battery housing for battery cells, in which a sheet forming cooling channels is fastened to a shell-shaped cover of the battery housing, the formed sheet bearing against battery cells accommodated in the battery housing.CN 106571501 A discloses a battery housing for battery cells, in which battery cells are covered by a hood, which has outwardly open channels on its top side and on two side surfaces, which channels are covered by a further hood.WO 2019 / 169080 A1 shows a battery housing in which a housing wall of the battery housing has cooling grooves for a cooling fluid which are open away from a battery and are closed by a planar plate, wherein the planar plate is inserted in a circumferential recessed shoulder of the housing wall in a surface-flush manner.US 2020 / 0028223 A1 discloses a battery housing in which a planar plate with a housing wall having cooling channels is centered via flange openings.WO 2020 / 121244 A1 discloses a cooling plate for a battery, in which a flat plate is glued onto a wall having cooling grooves.There is a constant need to reduce the manufacturing effort for cooling a battery module.The object of the invention is to show measures which allow cooling of a battery module with a low production outlay.The object is achieved according to the invention by a battery housing having the features of claim 1. preferred embodiments of the invention are specified in the dependent claims and the following description, which can each represent an aspect of the invention individually or in combination.One aspect of the invention relates to a battery housing for a battery module of a traction battery of a motor vehicle, having a housing for enclosing at least one battery cell of the battery module, at least one cooling groove, which is introduced into at least one housing wall of the housing and is open away from the battery cell, for the passage of a cooling fluid, and a cover, which is designed as a planar plate and is connected to the housing wall, for closing the at least one cooling groove, wherein the cover has a centring opening which can be plugged onto a centring body of the housing wall.The housing for the battery module can be based on a rectangular tube into which battery cells can be inserted and which is then closed at the end face. Because the at least one cooling groove is already introduced into the material forming the housing, a thermal conduction resistance between the battery cells and the cooling fluid in the cooling grooves can be kept particularly low. In any case, a heat-conducting resistance between an external cooling plate of a cooling system having cooling fluid through which a flow passes can be dispensed with and the material of the housing. Instead, the cooling fluid flowing through the cooling groove is in direct contact with the material of the housing. The cooling performance can thereby be improved.The at least one cooling groove is designed here to be open outwards away from the battery cells or an interior space bounded by the housing for receiving the battery cells. The cover to be connected to the respective housing wall can thereby be easily placed on the housing wall from the outside and fastened, for example by adhesive bonding or friction stir welding. The assembly is thus easily maintained. In addition, the cover is designed as a flat plate, so that protruding extensions, ribs or the like are avoided. The cover can thus easily be produced from a metal plate or plastic plate present as a semi-finished product exclusively by punching with a suitable punching tool. The manufacturing cost is thus very low. In this case, the realization is utilized that the housing already has a complex structure adapted for the intended application and is optionally remachined in any event and the at least one cooling groove can be produced cost-effectively during the remachined treatment, while no further processing steps are required for producing the cover. In particular in the case of a locally distributed production of the housing on the one hand and of the at least one cover on the other hand, cost savings can thereby be realized during production. The cooling groove formed in the housing wall allows the cover to be configured as a cost-effective planar plate, so that cooling of a battery module is made possible with a low production cost.The centering opening can be plugged or pressed onto the centering body, for example. As a result, the relative position of the cover relative to the housing wall to be covered, which has the cooling groove, can be precisely predefined without the cover having to have projections or tabs protruding therefrom. The centering and the positioning of the cover can thereby be achieved without a complicated three-dimensional shape of the cover.In particular, the cover has an inlet opening communicating with the cooling groove for supplying the cooling fluid and / or an outlet opening communicating with the cooling groove for discharging the cooling fluid. The cooling fluid can thereby be supplied and / or discharged through the cover. The corresponding inlet opening and / or outlet opening can easily be produced when producing the cover, in particular by punching, so that the production effort is kept low.Preferably, an inlet opening bounded by the cooling groove and the cover for supplying the cooling fluid and / or an outlet opening bounded by the cooling groove and the cover for discharging the cooling fluid is formed on an edge of the housing wall. The cooling fluid can thereby be supplied and / or discharged at the edge of the housing, in particular at the end face or transversely to the longitudinal extent of the housing. As a result, it is easily possible to connect a plurality of identically designed battery housings in series and to use the same cooling fluid for the temperature control of the battery cells in the different battery housings in a manner saving installation space. The outlet opening of one battery housing can be fluidically connected to an opposite inlet opening of another battery housing via a connection piece which is saving in installation space and is in particular configured merely as a seal.Particularly preferably, the housing is configured as an extruded rectangular profile, in particular a rectangular tube, wherein the at least one cooling groove is produced by pressure forming and / or machining. The housing, which can cover the battery cells from four different sides, can thereby be produced cost-effectively. On those housing walls on which the at least one cooling groove is to be produced, a thicker material thickness compared to a housing wall without a cooling groove can easily be provided. By machining or machining the material of the housing wall provided for this purpose, the at least one cooling groove can easily be introduced after the extrusion. For example, the housing can still be warm and easily formable immediately after the extrusion step and before a cooling step, such that before the housing solidifies in the cooling step, the at least one cooling groove can easily be embossed into the housing wall without machining. However, it is also possible to produce the cooling groove by machining only after the housing has been consolidated, for example by milling.In particular, the at least one housing wall is designed for removing mechanical loads, wherein a material of the housing wall delimiting the at least one cooling groove contributes to stiffening of the housing wall. The housing wall can be dimensioned to not only remove the dead weight and the weight force of the accommodated battery cells, but also, for example, impact forces occurring in the event of an accident ("crash"), in order to protect the battery cells from mechanical damage. In particular, the housing is load-bearing along an extrusion direction, wherein the at least one cooling groove is provided in one or more load paths of the housing. By configuring the at least one cooling groove, the mechanical behavior of the housing during the load transfer can be influenced. For example, a predetermined breaking point for a crash event can be provided with the aid of the cooling groove in order to dissipate impact energy by absorbing deformation work and to protect the battery cells accommodated in the housing.The cooling groove preferably has a shape which deviates from a straight course, wherein in particular the cooling groove runs in an angular and / or zigzag-shaped and / or meandering manner. The geometry and / or the course of the cooling groove can in principle be freely selected. As a result, the contact surface of the cooling fluid with the material of the housing to be temperature-controlled can be significantly increased. The cooling capacity can thereby be increased. In addition, the cooling fluid can be discharged at a higher temperature, which facilitates and makes more efficient the passive cooling of the cooling fluid, for example in a front radiator of the motor vehicle. The cooling efficiency can thereby be improved.In particular, the housing has at least two, preferably at least four, housing walls provided with at least one cooling groove, preferably with a plurality of cooling grooves. In contrast to an underbody plate provided for cooling the battery cells and through which a cooling fluid flows, the housing and the battery cells accommodated therein can be cooled from more than one side. The cooling performance and / or the cooling efficiency can thereby be improved.A further aspect relates to a battery module for a traction battery of a motor vehicle, having at least one battery cell and a battery housing, which can be configured and further developed as described above, for enclosing the at least one battery cell, wherein the battery cell bears directly or exclusively only via a heat-conducting layer against the housing wall provided with the at least one cooling groove. A heat transfer resistance between the battery cell to be cooled and the cooling fluid separated via the housing wall in a medium-tight manner can thereby be minimized. The cooling groove formed in the housing wall allows the cover to be configured as a cost-effective planar plate, so that cooling of a battery module is made possible with a low production cost.Preferably, the single active temperature control of the at least one battery cell is provided exclusively by the heat exchange of the at least one battery cell with the cooling fluid that can flow in the at least one cooling groove. An additional underbody cooling can be saved and / or replaced by the cooling capacity of the at least one cooling groove introduced in the at least one housing wall. The structural outlay for cooling the battery cells can thus be kept low at low cost.The invention is explained below by way of example with reference to the attached drawings on the basis of preferred exemplary embodiments, wherein the features illustrated below can represent an aspect of the invention both individually and in combination. The following are shown: FIG. 1 : shows a schematic perspective view of a battery housing before assembly, FIG. 2 : shows a schematic perspective view of the battery housing from FIG. 1 after assembly, FIG. 3 : shows a schematic sectional view of the battery housing from FIG. 2, and FIG. 4 : shows a schematic front view of an alternative embodiment of the battery housing from FIG. 2.The battery housing 10 illustrated in FIG. 1 can be used to accommodate battery cells in order to form a battery module for a traction battery for electrically driving a motor vehicle. The battery housing 10 has an extruded housing 12 which is produced from a plastic material and is designed as a rectangular profile and in which, for example, a dividing wall 14 which corresponds to the extrusion direction and runs in the longitudinal direction of the housing 12 is inserted in order to divide the housing 12 into a plurality of sub-chambers. For example, a plurality of cooling grooves 18, which in particular run in meandering fashion, are introduced in an upper housing wall 16 of the housing 12, through which cooling grooves a cooling fluid can flow in order to temperature control, in particular to cool and / or preheat, the housing 12 and the battery cells accommodated in the housing 12. With the aid of a cover 20 designed as a flat plate, the cooling grooves 18 can be closed, so that a cooling channel delimited by the cooling groove 18 of the housing wall 16 and an underside of the cover 20 is formed. Additionally or alternatively, at least one cooling groove closed by another cover can also be provided in the other walls of the housing 12, in order to correspondingly increase the cooling capacity for cooling the battery cells, as is illustrated in FIG. 3.As is shown in FIG. 2, the cover 20 can have a centering opening 22, which can be plugged onto a centering body 24 formed in the housing wall 16, in order to preset a defined relative position of the cover 20 relative to the housing wall 16, without the cover 20 requiring elevations protruding from the material plane of the cover 20. In the exemplary embodiment shown in FIG. 2, the cover 20 for the various cooling channels has in each case an inlet opening 26 and an outlet opening 28, via which the cooling fluid can enter and exit orthogonally to the extrusion direction of the housing 12. The respective cooling channel can be connected via the inlet opening 26 and the outlet opening 28 to a cooling circuit which in particular has an external heat exchanger, in particular a front cooler of the motor vehicle which is air-cooled by relative wind, in order to cool the heated cooling fluid back to a desired operating temperature, preferably passively.As shown in FIG. 4, additionally or alternatively at least one of the inlet openings 26 and / or one of the outlet openings 28 can be provided on the end face of the housing 12. For this purpose, the associated cooling groove 18 can be designed to be open toward the end side of the housing 12, so that the inlet opening 26 or the outlet opening 28 is produced at the end side of the housing between the cooling groove 18 and the cover 20.

Claims

Battery housing (10) for a battery module of a traction battery of a motor vehicle, having a housing (12) for enclosing at least one battery cell of the battery module, at least one cooling groove (18), which is introduced into at least one housing wall (16) of the housing (12) and is open away from the battery cell, for the passage of a cooling fluid, and a cover (20), which is designed as a planar plate and is connected to the housing wall (16), for closing the at least one cooling groove (18), characterized in that the cover (20) has a centring opening (22) which can be plugged onto a centring body (24) of the housing wall (16).Battery housing (10) according to Claim 1da, characterized in that the cover (20) has an inlet opening (26), which communicates with the cooling groove (18), for supplying the cooling fluid and / or an outlet opening (28), which communicates with the cooling groove (18), for discharging the cooling fluid.Battery housing (10) according to Claim 1 or 2da characterized in that an inlet opening (26), which is bounded by the cooling groove (18) and the cover (20), for supplying the cooling fluid and / or an outlet opening (28), which is bounded by the cooling groove (18) and the cover (20), for discharging the cooling fluid is formed on an edge of the housing wall (16).Battery housing (10) according to one of Claims 1 to 3, characterized in that the housing (12) is designed as an extruded rectangular profile, in particular a rectangular tube, wherein the at least one cooling groove (18) is produced by pressure forming and / or machining.Battery housing (10) according to one of Claims 1 to 4, characterized in that the at least one housing wall (16) is designed to remove mechanical loads, wherein a material of the housing wall (16) delimiting the at least one cooling groove (18) contributes to stiffening of the housing wall (16).Battery housing (10) according to one of Claims 1 to 5, characterized in that the cooling groove (18) has a shape configuration which deviates from a straight course, wherein in particular the cooling groove (18) runs at an angle and / or zigzag shape and / or meander shape.Battery housing (10) according to one of Claims 1 to 6da characterized in that the cover (20) is fastened to the housing wall (16) by adhesive bonding or friction stir welding.Battery housing (10) according to one of Claims 1 to 7da, characterized in that the housing (12) has at least two, preferably at least four, housing walls (16) provided with at least one cooling groove (18), preferably with a plurality of cooling grooves (18).Battery module for a traction battery of a motor vehicle, having at least one battery cell and a battery housing (10) according to one of Claims 1 to 8 for enclosing the at least one battery cell, wherein the battery cell bears directly or exclusively only via a heat-conducting layer against the housing wall (16) provided with the at least one cooling groove (18).Battery module according to Claim 9da, characterized in that the only active temperature control of the at least one battery cell is provided exclusively by the heat exchange of the at least one battery cell with the cooling fluid which can flow in the at least one cooling groove (18).

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