This application claims priority to German Provisional Patent Application No. DE 10 2021 201 840.8, filed on Feb. 26, 2021, and German Patent Application No. DE 10 2021 203 977.4, filed on Apr. 21, 2021, the contents of both of which are hereby incorporated by reference in their entirety.
The invention relates to an electric battery and to a motor vehicle, in particular to an electric vehicle with a purely electric drive.
For some time, electric batteries for motor vehicles have been realised in modular form with multiple battery cell modules which are arranged in a common battery housing where they are cooled through heat transfer to a coolant.
Solutions are known, with which the coolant is conducted through cooling plates which form a part of the battery housing and are additionally thermally coupled to the battery cell modules. By means of a common coolant supply, the coolant is distributed over the individual cooling plates and, having flowed through the cooling plates and absorbed heat from the battery cell modules accompanied by this, is again discharged via a common coolant discharge.
Often it proves to be problematic that with inadequate sealing of the fluid connection between the cooling plates and the coolant supply or coolant discharge the coolant can leak out into the external surroundings of the battery. A reliable sealing of the housing interior relative to the outer surroundings is therefore particularly important so that in the case of a damaged seal at the transition between coolant supply or coolant discharge and the cooling plates coolant leaked out there cannot enter the housing interior and damage the battery cell modules arranged there despite this.
Conventional sealing concepts, which are to prevent a leakage of coolant out of the coolant supply or coolant discharge and entry into the housing interior accompanied by this are technically involved and thus expensive to produce.
It is therefore an object of the present invention to create an improved embodiment for an electric battery which takes into account the problem mentioned above. In particular, an electric battery with an improved sealing concept is to be created which is characterised by a technically simple feasibility and thus also by reduced production costs.
This object is solved through the subject matter of the independent patent claim(s). Preferred embodiments are the subject matter of the dependent patent claim(s).
Accordingly, the basic idea of the invention is to equip an electric battery having multiple battery cell modules which are arranged in a common housing with a sealing device which ensures a sealing of the housing interior against the outer surroundings of the battery and also a sealing of the coolant supply/coolant discharge against the cooling plate that can be flowed through by the coolant. This proposal includes solutions with which for each individual battery cell module a separate cooling plate is provided, which is thus supplied with the coolant via the common coolant supply and from which the coolant, having flowed through the cooling plate, is again discharged via the common coolant discharge. According to the invention, such sealing device is provided for each cooling plate in this case. By means of the sealing device it can thus be ensured on the one hand that no coolant can leak out at the transition between coolant supply/coolant discharge and the respective cooling plate and on the other hand it is ensured independently of this that no coolant whatsoever can enter from the external surroundings into the housing interior.
An electric battery according to the invention includes a battery housing, preferentially of an electrically insulating plastic, which partially surrounds a housing interior and comprises at least one housing opening, preferentially multiple housing openings, wherein the at least one housing opening is sealed by means of a cooling plate. In at least one, preferentially each cooling plate present a coolant path that can be flowed through by a coolant is formed, which extends from a path inlet to a path outlet. Further, the battery cell includes at least one battery cell module arranged in the housing interior, preferentially multiple such battery cell modules for storing electric energy. Here, each battery cell module arranged in the housing interior is thermally coupled to one of the cooling plates. Practically, a cooling plate for cooling the battery cell module and a housing opening, via which the battery cell module can be introduced into the housing interior is thus provided for each battery cell module arranged in the housing interior. Further, the battery cell includes a coolant supply and discharge provided outside on the battery housing, which fluidically separated from the housing interior communicates with the coolant paths. The coolant supply channel serves for distributing the coolant into the coolant paths formed in the cooling plates. The coolant discharge channel serves for collecting the coolant having flowed through the coolant paths. To this end, the coolant supply channel and the coolant discharge channel both communicate fluidically with the coolant paths.
For each cooling plate of the battery cell, the battery cell includes a separate sealing device. According to the invention, each sealing device is arranged between the cooling plate and the battery housing so that it seals both the housing interior and also a transition from the coolant supply and discharge to the coolant path against the external surroundings of the battery housing.
In a preferred embodiment, the coolant supply and discharge for each cooling plate includes a coolant supply channel fluidically communicating with the path inlet and a coolant discharge channel fluidically communicating with the path outlet. In this embodiment, all coolant supply channels communicate fluidically with a common coolant distributor channel of the coolant supply and discharge and all coolant discharge channels communicate fluidically with a common coolant collector channel of the coolant supply and discharge. This embodiment simplifies the distribution of the coolant over the individual cooling plates and the collecting of the coolant having flowed through the cooling plates.
At least the coolant supply channels and at least the coolant discharge channels are at least partially formed by at least one recess formed outside on the battery housing, which is sealed in a fluid-tight manner by means of a cover preferentially formed in the manner of a tubular body that is fastened to the battery housing. This variant can be easily realised technically and requires only little installation space.
Particularly preferably, all sealing devices introduced above are each formed in one piece. Such sealing devices are particularly simple in construction so that cost advantages for producing the battery materialise, in particular when a larger quantity of battery cell modules and thus also a larger quantity of sealing devices are used.
In a preferred embodiment, each sealing device is arranged in the mounted state of the battery with a main portion between the cooling plate and the battery housing and with two sub-portions at the transition at least partially between the cooling plate and the coolant supply and discharge. Thus, an effective sealing of the housing interior relative to the external surroundings of the battery housing can be achieved. The same applies to the sealing of the coolant supply and discharge relative to the external surroundings of the battery. In addition to this, a sealing device formed in such a manner facilitates a simple mounting of the same on the battery housing.
Practically, the sealing devices can be preassembled on the battery housing during the course of the assembly of the battery. To this end it is conceivable to provide on the battery housing a receiving groove in which the sealing device prior to fastening the respective cooling plate on the battery housing is arranged, so that the sealing device is partially received in the same.
According to an advantageous further development, the main portion has a rectangular shape with two narrow and two wide sides. In this further development, the sub-portions each have an angular, preferentially a circular geometry. Each of the two sub-portions can each be connected to a narrow or wide side of the rectangular main portion by means of a preferentially linear intermediate portion. This variant is particularly easy to produce and thus cost-effective.
Particularly practically, the respective sealing device with the main portion surrounds a top side of the cooling plate facing the battery housing along its outer edge. In this variant, the respective sealing device with the first sub-portion surrounds the path inlet of the cooling plate and with a second sub-portion the path outlet of the cooling plate. This variant can be particularly easily mounted on the battery housing.
Practically, the sealing devices can each be formed in the manner of a sealing ring, preferably with a round, particularly preferably with a circular profile. Such sealing rings can also be particularly easily and thus cost-effectively produced.
According to another preferred embodiment, the coolant paths present in the cooling plates are formed by a hollow space with channel-like geometry formed in the respective channel plate. This allows an effective coupling of the coolant to the respective battery cell module so that waste heat generated by the respective battery cell module during the operation of the battery can be effectively transferred to the coolant.
According to a further advantageous further development, a thermal adapter layer is arranged between at least one, preferentially each battery cell module and the cooling plate assigned to this battery cell module. The adapter layer can be formed in particular by a heat-conducting paste or by a heat-conducting pad. In this way, the thermal coupling between the coolant flowing through the cooling plate and the battery cell module and thus the efficiency of the cooling process can be improved.
According to a further advantageous further development, the battery housing is arranged with an underside comprising the housing openings on a frame-like crash structure, preferentially of metal. In this way, the mechanical strength of the entire battery relative to external mechanical influences such as impacts or shocks, in particular when the battery is employed in a motor vehicle, is improved. Undesirable damage to the battery due to impact or shock can thereby be counteracted.
According to another advantageous further development, the coolant supply and discharge can comprise multiple mechanical stiffening elements. In this way, the mechanical strength of the electric battery is also improved further and damage through mechanical shocks, impacts and the like counteracted.
In another preferred embodiment, each battery cell module includes an electrical positive connection and an electrical negative connection. Further, the battery includes an electrical current conduction for supplying the battery cell modules arranged in the housing interior with electric energy or for providing the energy stored in the battery cell modules. The electrical current conduction includes a first electrical conductor rail and a second electrical conductor rail, each of an electrically conductive material, which are both at least partially arranged outside on the battery housing. The first conductor rail includes multiple rail elements by means of which a positive connection and a negative connection each are electrically connected to one another in the housing interior of adjacent battery cell modules. The second electrical conductor rail practically functioning as earth line is electrically connected to the negative connection of one of the battery cell modules. For each battery cell module, a first and a second cut-out are formed in the battery housing through which a rail element of the first conductor rail each electrically connecting the two adjacent battery cell modules is passed. According to the invention, the battery includes a cover of an electrically insulating plastic formed separately from the battery housing that can—detachably or non-detachably—be fastened to the same which covers the conductor rails in the region outside the housing interior.
According to an advantageous further development, the cover is formed U-shaped in profile with a U-base and two U-legs, wherein on the two U-legs a clamping structure for fixing the cover to the battery housing is present. By means of the clamping structure, the cover can be simply yet reliably fixed to the battery housing. In addition, a cover configured in such a manner is easy to produce and is thus accompanied by low manufacturing costs.
According to a further advantageous further development, a separating element of an electrically insulating plastic can be moulded onto the cover, in particular onto the U-base of the same. Practically, the separating element and the cover are formed in one piece and material-uniformly. The said separating element can subdivide the interior delimited by the cover and the battery housing into a first compartment, in which—in the assembled state of the battery—the first conductor rail is received, and into a second compartment, in which the second conductor rail is received. In this way, a spatial electrical separation of the two electrical conductor rails from one another is ensured as a result of which in particular an undesirable electrical short circuit between the two electrical conductor rails, even in the case of vibrations and the like, which in the absence of the separating element, could lead to a brief contact of the two conductor rails, is avoided.
Particularly preferably, the separating element can comprise a first element portion by means of which a film hinge is hinged to a second element portion of the separating element. In this variant, the first element portion is firmly connected to the U-base, in particular integrally moulded on the same, whereas the second element portion can be or is detachably fastened to the U-base. With a separating element configured in such a manner, the second conductor rail can be easily preassembled initially in the second compartment. Following this, the cover with the preassembled second conductor rail can be fastened to the battery housing with the first conductor rail preassembled there. Following the arranging of the second conductor rail on the cover the separating element can be folded over by means of the film hinge and the second element portion fastened to the U-base by means of a clip-on connection or snap-on connection. This makes possible a stable fixing of the separating element to the cover or to the U-base of the same. Preferably, following the fastening by means of the clip-on or snap-on connection, the separating element and the U-base together surround the second compartment.
In another preferred embodiment, a mechanical stiffening structure with multiple preferentially rib-like stiffening elements is formed on the electrical current conduction. In this way, the mechanical stiffness of the electrical current conduction and thus its resistance to external influences, in particular mechanical impacts or mechanical shocks or the like can be increased.
Practically, the electrical current conduction can be arranged on a side of the battery housing located opposite the coolant supply and discharge. This measure simplifies both the mounting of the coolant supply and discharge and also of the electrical current conduction on the battery housing.
Particularly practically, the cover is an extruded part. A cover configured in such a manner can be manufactured particularly cost-effectively.
Further, the invention relates to a motor vehicle, in particular an electric vehicle with purely electric drive. The motor vehicle includes a body and an electric battery according to the invention introduced above. The advantages of the battery according to the invention explained above therefore apply also to the motor vehicle according to the invention. Preferably, the battery includes the crash structure explained above. In this case, the battery is preferably connected to the body of the motor vehicle via the crash structure.
Further important features and advantages of the invention are obtained from the subclaims, from the drawings and from the associated figure description by way of the drawings.
It is to be understood that the features mentioned above and still to be explained in the following cannot only be used in the respective combination stated, but also in other combinations or by themselves without leaving the scope of the present invention.
Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description wherein same reference numbers relate to same or similar or functionally same components.
It shows, in each case schematically:
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The coolant distributor channel 9a serves for supplying the coolant into the coolant paths 6 formed in the cooling plates 5. The coolant collector channel 10a serves for collecting the coolant having flowed through the coolant paths 6. The coolant supply channels 9 and the coolant discharge channels 10 as well as the common coolant distributor channel 9a and the common coolant collector channel 10a can each be at least partially formed by at least one recess 13 formed outside on the battery housing 4, which is sealed in a fluid-tight manner by means of a cover 14 preferentially formed in the manner of a tubular body fastened to the battery housing 4.
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The first conductor rail 32a includes multiple separate rail elements 33, by means of which a positive connection 30a and a negative connection 30b each of two adjacent battery cell modules 7 in the housing interior 2 are electrically connected to one another. In this way, the individual battery cell modules 7 can be electrically connected in series to one another. For realising such an electrical series connection, the second electrical conductor rail 32b is electrically connected to the negative connection 30b of one of the battery cell modules 7, which for illustration is additionally marked with the reference number 7* in
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The assembly of the electric battery 1 can take place as follows:
Initially, the first conductor rail 32a with the rail elements 33 can be preassembled on the battery housing 4, so that the rail elements 33 following such a preassembly engage through the first and second cut-outs 34a, 34b towards the inside, into the housing interior 2. Following this, the individual battery cell modules 7 can be introduced via the respective housing opening 3 into the housing interior 2 and fixed to the battery housing 4 there. The fastening of the battery cell modules 7 to the battery housing 4 can take place for example with the help of suitable screw connections (not shown). During the course of the arrangement of the battery cell modules 7 in the housing interior 2, the respective electrical positive connections 30a and electrical negative connections 30b of the battery cell modules 7 are then electrically and mechanically connected to the preassembled rail elements 33—for example by means of plug connections (not shown).
Following this, the already mentioned thermal adapter layer 21—for example as heat-conducting paste, can be optionally applied to the undersides of the battery cell modules 7 facing the housing openings 3.
In a next mounting step, the second conductor rail 32b is mounted to the cover 35. To this end, the second conductor rail 32b is initially preassembled on the cover 35 and for this purpose arranged in the region of the separating element 38. Following this, the second element portion 38b is folded round about the second conductor rail 32b by means of the film hinge 40. By subsequently fixing the second element portion 38b of the separating element 38 to the U-base 36c of the cover 35 by means of the clip-on connection 41, the second conductor rail 32b is permanently fixed in the second compartment 39b of the interior 39 formed in this manner.
The unit of second conductor rail 32b and cover 35 formed in this way is subsequently fastened with the help of the clamping structures 37 to a housing collar 46 (see
Following this, both the first conductor rail 32a and also the second conductor rail 32b are covered by means of the cover 35 and fixed on the battery housing 4 as desired.
Number | Date | Country | Kind |
---|---|---|---|
10 2021 201 840.8 | Feb 2021 | DE | national |
10 2021 203 977.4 | Apr 2021 | DE | national |