Motor vehicle battery

A motor vehicle battery includes a battery housing. The battery housing has a housing interior bounded in sections by a housing frame and a housing base. The motor vehicle battery further includes a plurality of battery modules arranged in the housing interior. The motor vehicle battery further includes at least one first cooling duct. The at least one first cooling duct is formed in the region of the housing base, for cooling the battery modules from a first side. The housing interior is bounded by a housing cover or by a housing lid opposite the housing base. At least one second cooling duct for cooling the battery modules from a second side is formed in the region of the housing cover or of the housing lid.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to German Patent Application No. DE 10 2017 128 529.6, filed Dec. 1, 2017, the entire disclosure of which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The invention relates to a motor vehicle battery.

BACKGROUND OF THE INVENTION

DE 10 2015 115 875 A1, which is incorporated by reference herein, discloses a motor vehicle battery designed as a traction battery of a motor vehicle. The motor vehicle battery disclosed there comprises a battery housing, which defines a housing interior that is bounded at least in sections by a housing frame and a housing base of the battery housing. A plurality of battery modules are positioned in the housing interior of the battery housing of the motor vehicle battery. In the region of the housing base, the motor vehicle battery has at least one cooling duct in order to cool the battery modules via the housing base of the battery housing. Each battery module has a plurality of battery cells.

DE 10 2012 022 765 A1, which is incorporated by reference herein, discloses an arrangement consisting of two battery modules of a motor vehicle battery, wherein each battery module has a plurality of battery cells. The battery cells of each battery module are pressed together, wherein a cooling plate for cooling the battery cells is provided between the battery modules arranged one above another or the battery cells of the battery modules arranged one above another.

DE 10 2013 021 597 A1, which is incorporated by reference herein, discloses a further battery module of a motor vehicle battery, which has a plurality of battery cells. The battery module disclosed there has a heat removal system in order to remove heat from a housing of the battery module that accommodates the plurality of battery cells.

DE 10 2012 012 663 A1, which is incorporated by reference herein, discloses a battery module with a plurality of battery cells, which is referred to as a battery pack. The battery cells are accommodated in a housing of the battery module. The housing is assembled from a trough and a lid closing the trough. A separating body is arranged between the trough and the battery cells of the battery module. The separating body and the trough bound an intermediate space for the conduction of a coolant.

DE 10 2013 210 932 A1, which is incorporated by reference herein, discloses a further battery housing for a battery module, which has a plurality of battery cells. The housing of the battery module comprises a wall with a duct for receiving a temperature-control agent, which serves for controlling the temperature of the battery cells of the battery module.

From the above-mentioned prior art, it is accordingly known either to cool the battery modules of the motor vehicle battery via the battery housing of the motor vehicle battery, or to undertake the cooling of the battery cells of a battery module via a housing of the battery module. The invention present here relates to the cooling of battery modules of the motor vehicle battery via the battery housing of the motor vehicle battery and not to the cooling of battery cells of the individual battery modules via the housing of individual battery modules.

From the above-cited prior art relating to the cooling of battery modules via the battery housing of a motor vehicle battery, it is known to cool the battery modules from the housing base. Cooling of the battery modules can therefore be ensured to a certain extent, but uniform cooling of the battery modules is not possible. The service life of the battery modules is thereby limited.

SUMMARY OF THE INVENTION

There is a need for a motor vehicle battery with improved cooling of the battery module. According to an example, a motor vehicle battery includes a battery housing. The battery housing includes a housing interior that is bounded by a housing cover or by a housing lid opposite the housing base. At least one second cooling duct for cooling the battery modules from a second side is formed in the region of the housing cover or of the housing lid. In the case of the motor vehicle battery according to aspects of the invention, the battery modules of same can be cooled via the housing base and the housing cover or the housing lid from two opposites sides. Uniform cooling and therefore controlling of the temperature of the battery modules is possible therewith, as a result of which the service life of the battery modules can be increased.

According to an advantageous development, each battery module is thermally coupled both to the housing base and to the housing cover or to the housing lid in order to cool the respective battery module on both sides. Via the thermal coupling of the battery modules on one side to the housing base and on the other side to the housing cover or to the housing lid, particularly advantageous cooling of the battery modules of the motor vehicle battery on both sides is possible. The service life of the battery modules can thereby be increased further.

The battery modules are thermally coupled to the housing base and the housing cover or the housing lid via a heat-conducting medium, which is arranged between the battery modules and the housing base and also the housing cover or the housing lid.

The heat-conducting medium arranged between the housing base and the battery modules and also between the housing cover or the housing lid and the battery modules can compensate for tolerances, unevennesses and the like of the battery housing and can always ensure an optimum thermal contact connection of the battery modules to the housing base and the housing cover or the housing lid in order thereby to further increase the service life of the battery modules.

According to an advantageous development, the housing base has a wall segment facing the battery modules and a wall segment facing away from the battery modules, between which wall segments at least one first cooling duct or multiple first cooling ducts are formed. The battery modules are thermally coupled to that wall segment of the housing base, which faces the battery modules.

The housing cover or the housing lid has a wall segment facing the battery modules and a wall segment facing away from the battery modules, between which wall segments at least one second cooling duct or multiple second cooling ducts are formed. The battery modules are thermally coupled to that wall segment of the housing cover or of the housing lid, which faces the battery modules.

That wall segment of the housing base which faces the battery modules and that wall segment of the housing base which faces away from the battery modules are spaced apart in first sections, in which the at least one first cooling duct or each first cooling duct is formed, and, in second sections, in which no cooling duct is formed, are connected directly or indirectly via a central wall segment.

That wall segment of the housing cover or of the housing lid which faces the battery modules and that wall segment of the housing cover or of the housing lid which faces away from the battery modules are spaced apart in first sections, in which the at least one second cooling duct or each second cooling duct is formed, and, in second sections, in which no cooling duct is formed, are connected directly or indirectly via a central wall segment.

The cooling ducts are bounded by the respective wall segment which faces the battery modules and by the respective wall segment which faces away from the battery modules or by the respective wall segment which faces the battery modules and by the respective central wall segment.

Such a design of the battery housing in the region of the housing base and also of the housing cover or the housing lid is particularly preferred in order to form the cooling ducts which serve for cooling the battery modules on both sides. The cooling ducts, which are formed between the respective wall segment facing the battery modules and the respective wall segment facing away from the battery modules are bounded at least by the respective wall segment facing the battery modules and are oppositely bounded either by the wall segment facing away from the battery modules or by an additional central wall segment. Along with a simple design, this permits optimum cooling of the battery modules on both sides in order to increase the service life of same.

According to an advantageous development, the housing frame has outer longitudinal members and inner longitudinal members and also outer crossmembers and inner crossmembers. The housing base is connected to the outer and inner longitudinal members and to the outer and inner crossmembers of the housing frame.

The housing cover or the housing lid is connected to the outer and inner longitudinal members and to the outer and inner crossmembers of the housing frame.

The housing base and the housing cover or the housing lid are designed as a single shell in edge sections adjacent to the outer crossmembers and longitudinal members. The housing base and the housing cover or the housing lid are designed in multi-shell form in a central section adjacent to the respective edge section. The housing base and the housing cover or the housing lid have deformation beads in the edge sections, in which same are formed as a single shell. A battery housing of this type not only ensures cooling of the battery modules on both sides from the housing base and also from the housing cover or the housing lid, but furthermore also ensures optimum reinforcement of the motor vehicle battery in order to increase the crash safety of the motor vehicle battery. Forces acting on the motor vehicle battery, namely on the battery housing, in the event of a crash can be dissipated via the deformation beads in order to protect the battery modules as such against damage.

According to an advantageous development, meandering cooling ducts and/or cooling ducts in the counterflow principle with a feed line and an opposed return line are formed in the region of the housing base and the housing cover or the housing lid. Cooling ducts of this type permit optimum removal of heat on both sides from the battery modules and thus uniform cooling of same, as a result of which the service life of the battery modules can be increased further.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a motor vehicle battery, designed as a traction battery, of a motor vehicle, as is used in electric vehicles or hybrid vehicles.

FIGS. 1, 6 and 7each show a top view of a motor vehicle battery10according to aspects of the invention. Such a motor vehicle battery10has a battery housing11and also a plurality of battery modules12accommodated in the battery housing11.

Vertical projection areas of the battery modules12accommodated by the battery housing11are shown in a dashed line guide inFIG. 6.

Each of the battery modules12has battery cells (not shown) which are electrically contacted, forming the respective battery module12.

The battery housing11has a housing frame13, a housing base14, a housing cover15or a housing lid15. The housing frame13has outer longitudinal struts16and at least one inner longitudinal strut17. Furthermore, the housing frame13has outer transverse struts18and also, in the exemplary embodiment illustrated, has a plurality of inner transverse struts19.FIG. 7shows vertical projection areas of the outer and inner longitudinal struts16,17and of the outer and inner transverse struts18,19in a dashed line guide.

The housing frame13with its longitudinal struts16,17and its transverse struts18,19extends between the housing base14and the housing cover15or the housing lid15. The housing frame13, the housing base14and the housing cover15or the housing lid15define an interior20of the battery housing11, in which the battery modules12are accommodated.

A protective plate21extends under the housing base14of the battery housing13in order to protect the motor vehicle battery10, which is installed in the region of an underbody of the motor vehicle, against damage, wherein the protective plate21is mounted on the housing frame13of the battery housing11.

The battery modules12of the motor vehicle battery10can be cooled firstly in the region of the housing base14via at least one first cooling duct22, which is formed in the region of the housing base14, and also secondly in the region of the housing cover15or the housing lid15via at least one second cooling duct23, which is formed in the region of the housing cover15or of the housing lid15, in order thus to cool, and therefore uniformly control the temperature of, the battery modules12from two opposite sides.

Each battery module12can accordingly be cooled, or the temperature thereof can be controlled, firstly from a first, lower side via at least one first cooling duct22or each of multiple first cooling ducts22of the housing base14and secondly from an opposite upper, second side via at least one second cooling duct23or each of multiple second cooling ducts23of the housing cover15or of the housing lid15.

For this purpose, each battery module15is thermally coupled both to the housing base14and to the housing cover15or the housing lid15, in the exemplary embodiment shown via a heat-conducting medium24which is positioned between the respective battery module12and the housing base14and also via a heat-conducting medium24which is positioned between the respective battery module12and the housing lid15or the housing cover15. Tolerances and unevennesses in the structure of the battery housing11can be compensated for via the heat-conducting medium24or the heat-conducting substance such that an optimum thermal contact connection of the battery modules12downward to the housing base14and upward to the housing cover15or the housing lid15is always ensured.

The housing base14has a wall segment14afacing the battery modules12and a wall segment14bfacing away from the battery modules12. The at least one first cooling duct22or each first cooling duct22is formed between said wall segments14a,14b. The battery modules12are thermally coupled to that wall segment14aof the housing base14which faces the battery modules12, in particular via the heat-conducting medium24which is positioned between the wall segment14afacing the battery modules12and the battery modules12.

The housing cover15or the housing lid15like the housing base14has a wall segment15afacing the battery modules12and a wall segment15bfacing away from the battery modules12. The at least one second cooling duct23or each second cooling duct23is as formed between these wall segments15a,15bof the housing cover15or of the housing lid15. The battery modules12are in contact with that wall segment15aof the housing cover15or the housing lid15which faces the battery modules12, in particular via the heat-conducting medium24which is positioned between the battery modules12and the wall segment15afacing the battery modules12.

As can best be gathered fromFIGS. 4 and 5, that wall segment14aof the housing base14which faces the battery modules12and that wall segment14bof the housing base14which faces away from the battery modules12are spaced apart from each other in first sections25, whereas, in second sections26, said wall segments14a,14bare connected directly to each other in the exemplary embodiment shown. Similarly, in the region of the housing cover15or of the housing lid15, the wall segment15afacing the battery modules12and the wall segment15bfacing away from the battery modules12are spaced apart from each other in first sections27, and, in second sections28, are connected directly to each other in the exemplary embodiment shown.

The cooling ducts22,23are then formed in the region of the first sections25,27of housing base14and housing cover15or housing lid15. In the exemplary embodiment shown, the cooling ducts22,23are bounded in the region of the first sections25,27by the wall segments14a,14bor15a,15bwhich are spaced apart from each other.

It is possible that, in contrast to the exemplary embodiment shown, a central wall segment is arranged between the respective wall segment14aor15a, which faces the battery modules12, and the respective wall segment14bor15b, which faces away from the battery modules12, in the region of the housing base14and/or in the region of the housing cover15or of the housing lid15, via which central wall segment then, in the region of the second sections26,28of housing base14and housing cover15or housing lid15, the wall segments14a,14bor15a,15bof same are indirectly connected to each other. In this case, the cooling ducts22,23are then bounded by the wall segments14a,14bfacing the battery modules12, and also by the central wall segments (not shown).

The connection of the wall segments14a,14bor15a,15bof housing base14and housing cover15or housing lid15can take place in an integrally bonded and/or force-fitting and/or form-fitting manner, for example by welding, in particular cold pressure welding, soldering, adhesive bonding or the like. The wall segments14a,14band15a,15bof housing base14and housing cover15or housing lid15are preferably composed here of a metallic material, such as, for example, a steel sheet or an aluminum sheet.

The longitudinal members16,17and crossmembers18,19of the housing frame13are also preferably manufactured from a metallic material, such as, for example, in the form of extruded profiles from steel or aluminum. The connection of the housing base14to the housing frame13and of the housing cover15or housing lid15to the housing frame13can take place in turn in an integrally bonded and/or force-fitting and/or form-fitting manner, in particular in turn by welding, in particular cold pressure welding, soldering, adhesive bonding or the like.

As already stated, the housing frame13comprises the outer longitudinal members16, the outer crossmembers18, at least one inner longitudinal member17and the inner crossmembers19. The housing base14and the housing lid15or the housing cover15comprise the wall segments14a,15afacing the battery modules12, and also the wall segments14b,15bfacing away from the battery modules12.

In a particularly preferred refinement of the invention, it is provided that the housing base14and the housing cover15or the housing lid15are merely of single-shell design in a preferably encircling edge section of same, which is adjacent to the outer crossmembers18and the outer longitudinal members16, wherein a cutout of such an edge section29is shown inFIG. 2.

Housing base14and housing cover15or housing lid15are of multi-shell design in a central section30adjacent to such a single-shell edge section29on the inside.

In the multi-shell central section30, the wall segments14a,15afacing the battery modules12, and also the wall segments14b,15bfacing away from the battery modules12are present, as is optionally also a central wall segment, which is not shown.

By contrast, in the single-shell edge section29, only one of said wall segments is present, in the exemplary embodiment shown the wall segment14a,15awhich faces the battery modules12and is extended from the multi-shell central section30into the single-shell edge region29.

The cooling ducts22,23which have already been mentioned are formed where the housing base14and the housing cover15or the housing lid15are of multi-shell design. The cooling ducts22,23are formed here where, in the vertical projection, the housing base14and the housing cover15or the housing lid15cover the battery module12.

In order to form said cooling ducts22,23, in the first sections25,27the wall segments14a,15afacing the battery modules12and the wall segments14b,15bfacing away from the battery modules are spaced apart from housing base14and housing cover15or housing lid15with the formation of intermediate spaces or cavities. Furthermore, in these regions in which the housing base14and the housing lid15or the housing cover15cover the battery modules12in vertical projection, the cooling ducts22,23are separated or spaced apart from one another via the second sections26,28. Where, in the vertical projection, the housing base14and the housing cover15or the housing lid15cover the inner transverse struts19and the inner longitudinal struts17, only the second sections26,28of the multi-shell housing base14or of the multi-shell housing cover15or the multi-shell housing lid15are formed, i.e. no cooling ducts, as a result of which optimum connection of housing base14and housing cover15or housing lid15to the inner longitudinal member17or the inner crossmembers19is ensured.

The housing base14and the housing cover15or the housing led15is of single-shell design in the respective edge section29, in which the housing base14and the housing cover15or the housing lid15engage on the outer longitudinal members16and the outer crossmembers18.

In this edge section29, the housing base14and the housing cover15or the housing lid15are connected in an encircling manner to the housing frame13, namely to the outer longitudinal members16and outer crossmembers18.

The housing base14and the housing cover15or the housing lid15are furthermore connected to the housing frame13in the region of the inner members17,19. This permits optimum reinforcement of the motor vehicle battery and also optimum cooling of the battery modules12since the penetration of air between the battery modules12and the housing base14and also the housing cover15or the housing lid15is prevented and optimum thermal coupling of the battery modules12to the housing base14and to the housing cover15or the housing lid15is made possible.

In these connecting regions which, as already mentioned, can be formed in an integrally bonded and/or form-fitting and/or force-fitting manner, a seal can additionally be provided. A sealing element is preferably arranged here between that respective wall segment14a,15aof housing base14or housing cover15that faces the battery modules12and the respective member16,17,18,19of the housing frame13.

Deformation beads31are preferably formed in the edge section29. By means of the deformation beads31, forces acting on the battery housing11in the event of a crash can be dissipated by targeted deformation in the region of the deformation beads31, in order to avoid damage to the battery modules12.

Forces in the event of a crash can be absorbed in the respective edge section29, in which housing base14and housing cover15or housing lid15are preferably of single-shell design and in which no cooling of the battery modules12is required.

By contrast, in the central section30, in which the battery modules12have to be cooled and in which there is a greater rigidity requirement, there is no risk of damage to the cooling ducts22,23and to the battery modules12.

As can best be gathered fromFIGS. 1, 6 and 7, which each show a top view of a motor vehicle battery10and accordingly of housing lid15or housing cover15, in the exemplary embodiment shown two meandering cooling ducts23which are each designed in the counterflow principle, specifically with a feed line23aand an opposed return line23b, are formed in the region of the housing cover15or housing lid15.

An inlet connection32for the feed line23aof the respective cooling duct23and an outlet connection33for the return line23bof the respective cooling duct23are formed here on a common transverse side of the battery housing11of the motor vehicle battery10.

The respective cooling duct23extends from said transverse side, on which the inlet connection32and the outlet connection33are formed, in the longitudinal direction of the motor vehicle battery10toward the opposite transverse side of same.

Inlet connection32and the outlet connection33can be formed on that wall segment14a,15aof housing base14and housing cover15or housing lid15which faces the battery modules12or on that wall segment14b,15bof housing base14and housing cover15or housing lid15which faces away from the battery modules12.

The respective cooling duct23extends over a plurality of battery modules12, which are arranged consecutively in the longitudinal direction, forming the meandering interlacing of feed line23aand return line23b.

The feed line23aextends here on the inside with respect to the inner longitudinal member17in an inner region of the motor vehicle battery. The respective return line23bextends on the outside. Accordingly, the feed line23aruns in the inner region in which the battery modules12are at the highest temperature. The return line23bextends on the outside over colder sections of the battery modules12. By this means, heat can be homogeneously removed from the battery modules12with lower temperature spreading in the battery modules12.

The contouring of the cooling ducts23shown for the housing cover15or the housing lid15inFIGS. 1, 6 and 7is also present in the region of the housing base14. By this means, optimum cooling of the battery modules12on both sides is possible.

The inlet connection32and the outlet connection33of the respective cooling duct23each preferably extend perpendicularly to the housing cover15or to the housing lid15, wherein corresponding connections are also present in the region of the housing base14.

The invention permits optimum cooling of a motor vehicle battery10, which is designed as a traction battery, namely cooling on both sides and simultaneously of a plurality of battery modules12of the motor vehicle battery10via the housing base14and the housing cover15or the housing lid15of the battery housing11. By this means, the service life of the battery modules12can be increased. Furthermore, in a particularly preferred embodiment, the crash safety for the motor vehicle battery10can be increased.