Cover for electrically coupling multiple storage cells of an electrical energy storage module

A cover electrically couples multiple storage cells of an electrical energy storage module. The cover has electrically conductive contact sockets which are embedded in an electrically insulating material of the cover and taper inwards on their insides, and into which terminals of the storage cells can be inserted to make electrical contact. Two connections are provided, one of which forms a positive terminal and the other of which forms a negative terminal of the electrically coupled storage cells. Multiple conductors electrically couple the storage cells, in particular for coupling the storage cells in series, in a predefined manner. The conductors are completely accommodated inside the cover, and the cover can be mounted on the storage cells such that it can be detached non-destructively.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a cover for electrically coupling a plurality of storage cells of an electrical energy storage module, to an electrical energy storage module having such a cover, and to a motor vehicle having such an energy storage module.

There are currently many possible ways of electrically coupling the individual storage cells of an electrical energy storage module to one another in the prior art. The poles of the storage cells are usually connected to cell connectors in such a manner that the storage cells are connected in series. In this case, the cell connectors are welded to the poles of the storage cells, in which case these connections cannot be released in a non-destructive manner. However, in the event of damage to a storage cell, the entire energy storage module must be replaced, which is associated with high costs.

A further possible way of coupling storage cells by means of an attachable carrier plate is known, for example, from DE 10 2011 087 040 A1.

An object of the present invention is to provide a cover for electrically coupling a plurality of storage cells of an electrical energy storage module, which cover provides easier handling.

One exemplary embodiment of the invention provides a cover for electrically coupling a plurality of storage cells of an electrical energy storage module. The cover includes electrically conductive contact sockets which are embedded in an electrically insulating material of the cover, taper inward (that is to say in the direction away from the storage cells) on their inner sides and into which poles of the storage cells can be inserted so as to make electrical contact. Two connections, one of which forms a positive pole and the other of which forms a negative pole of the electrically coupled storage cells, are provided, as well as a plurality of conductor tracks for electrically coupling the storage cells, in particular for coupling the storage cells in series, in a predefined manner. The conductor tracks are completely accommodated inside the cover, wherein the cover can be mounted on the storage cells such that it can be released in a non-destructive manner.

The contact sockets are preferably accommodated in the cover in such a manner that, of the outer sides of the contact sockets, at most the sides facing the storage cells are exposed. In this case, the contact sockets would not project beyond the outer side of the cover. However, it is also possible for the contact sockets to project somewhat beyond the outer side of the cover, in particular to project beyond the outer side by at most 30% of the contact socket depth. In this case, the contact socket depth is the depth inside the contact socket along the insertion direction of the poles of the storage cells.

The conductor tracks are completely accommodated inside the cover, which means that the conductor tracks are not externally exposed to the environment surrounding the cover. The advantage of this exemplary embodiment is that this creates a single-piece compact cover which is already fastened by pushing or plugging it onto the poles of the storage cells since, as a result of the tapering contact sockets, the cover is fastened to the energy storage module to a certain degree as it is plugged onto the poles. As a result of the cover which can be removed in a non-destructive manner, in the event of a defect in an individual storage cell, the cover can be removed in order to replace an individual storage cell and can be plugged on again after the defective storage cell has been replaced.

According to another exemplary embodiment of the invention, the contact sockets are conical on their inner sides. The contact sockets are therefore used, on the one hand, for guidance during plugging on and therefore for orienting the cover with respect to the energy storage module and, on the other hand, for fastening the cover to the energy storage module by virtue of the poles being pushed into the conical contact sockets and therefore being held therein in a frictionally engaged manner.

According to another exemplary embodiment of the invention, the cover has an at least three-layer structure, wherein a conductor track layer is embedded between two electrically insulating cover layers. The two cover layers therefore form touch protection and the conductor track layer in between can be adapted, depending on the desired storage cell connection or coupling, such that different covers with different connections, for example covers for a serial electrical connection of the storage cells and covers for a parallel electrical connection of the storage cells, can be provided with relatively little effort.

According to another exemplary embodiment of the invention, the cover has a cavity for liquid coolant or refrigerant. The advantage of this exemplary embodiment is that the waste heat of the energy storage module is dissipated at the top in the region of the poles and conductor tracks. In the prior art, the energy storage modules are often cooled at the bottom, that is to say on the opposite side of the storage cells, but there is a greater need for cooling on the side of the poles.

According to another exemplary embodiment of the invention, the cavity is adjacent to the conductor tracks, but is outside the conductor tracks.

According to another exemplary embodiment of the invention, the cover respectively has an inlet and an outlet which open into the cavity and via which coolant or refrigerant can be supplied and discharged.

According to another exemplary embodiment of the invention, the coolant is a phase change material, in particular a two-phase phase change material.

According to another exemplary embodiment of the invention, the cavity for the coolant or refrigerant is provided by a pipe which, in order to form the conductor tracks, is coated with electrically conductive material in sections or is composed of sections of electrically conductive material and electrically insulating material.

The invention also provides an electrical energy storage module having a multiplicity of storage cells which are electrically coupled using a cover according to one of the preceding exemplary embodiments.

According to one exemplary embodiment of the energy storage module, the storage cells are lithium ion batteries.

The invention also provides a motor vehicle having such an electrical energy storage module.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1is a schematic three-dimensional illustration of a cover1and of a multiplicity of storage cells2(only some are provided with a reference sign).FIG. 2is a schematic detailed view of a contact socket and of a section of a conductor track in the cover fromFIG. 1. The storage cells2are preferably prismatic, rechargeable lithium ion batteries. The multiplicity of storage cells2are preferably electrically connected in series with one another, but parallel coupling would also be conceivable depending on the application. This multiplicity of storage cells2which are electrically coupled to one another and are assigned to a single cover1form, together with the cover1, an electrical energy storage module3. In motor vehicles, a plurality of such energy storage modules3are usually electrically connected in parallel with one another and form an electrical energy store which provides the energy at least for driving the motor vehicle. The storage cells2each have two poles4, more precisely an anode terminal and a cathode terminal, which are arranged on the same side of the storage cell2. The poles4(only some are provided with a reference sign) project from the storage cell2and taper their outer circumference in the direction away from the storage cell2. In particular, the poles4taper a diameter of their circular cross section in the direction away from the storage cell2. The poles4are preferably conical, cone-shaped or frustoconical.

The cover1is preferably prismatic and has contact sockets5(only some are provided with reference signs) which are embedded in the cover1and into which the poles4of the storage cells can be inserted. The inner side of a contact socket5is respectively adapted to the outer side of the pole4assigned to this contact socket, that is to say they have a substantially corresponding form, with the result that the inner sides of the contact sockets5rest against the outer sides of the poles4as well as possible in order to establish good electrical contact. The contact sockets5of an energy storage module3are connected to one another by way of conductor tracks6in such a manner that the desired coupling of the storage cells2, for example an electrical series or parallel circuit, is implemented. For example, as illustrated inFIG. 1, an anode terminal of a storage cell2can be respectively connected to a cathode terminal of an adjacent storage cell2by virtue of the contact sockets5in contact with these terminals being electrically connected by way of a conductor track6. The conductor tracks6, in particular the ends of the conductor tracks6, are connected to the contact sockets5in an electrically conductive manner, in particular releasably in a non-destructive manner. For example, the conductor tracks6can be welded or soldered to the contact sockets5.

However, it is also possible for the contact sockets5, for example two contact sockets, to each be formed in one piece with a conductor track6. The conductor tracks6and the contact sockets4are embedded in an electrically insulating material7of the cover1. In this case, the conductor tracks6are preferably not exposed to the outside (that is to say to the environment surrounding the cover1) at any point. The contact sockets5are at least predominantly embedded in the cover1, and the contact sockets5are preferably accommodated in the cover1in such a manner that, of the outer sides of the contact sockets, at most the sides8facing the storage cells2are exposed. In this case, the contact sockets would not project beyond the outer side of the cover. However, it is also possible for the contact sockets to project beyond the outer side of the cover, in particular to project beyond the outer side by at most 30% of the contact socket depth. In this case, the contact socket depth is the depth inside the contact socket5along the insertion direction of the poles4of the storage cells2.

The contact sockets5are tapered on their inner side in the direction away from the storage cell2along an insertion direction of the poles4. In particular, the contact sockets5on their inner side taper a diameter of their circular cross section (perpendicular to the insertion direction) in the direction away from the storage cell2. The contact sockets5are preferably conical, cone-shaped or frustoconical. The cover1can, but need not necessarily, be releasably connected to the remaining energy storage module (not illustrated) or to a frame (not illustrated) holding the energy storage modules by means of screw connections9. The cover1may be produced from rigid materials. The cover1may likewise be produced from flexible materials, with the result that it is flexible. The latter would facilitate plugging of the contact sockets5onto the poles4and therefore the application of the cover1to the storage cells2and would ensure a better frictionally engaged hold.

Various implementations are possible. The electrically insulating material7may be molded as a molding compound around the contact sockets5and conductor tracks6. In addition, the electrically insulating material7may be in the form of two plates, one plate facing the storage cells2and one plate facing away from the storage cells2, between which the conductor tracks6are formed in the form of a third layer. The plates may be rigid or flexible plates. In this case, the conductor track layer could be countersunk in one of the two plates or in both plates made of electrically insulating material. The conductor tracks6may be in the form of a multiplicity of individual rod-shaped flat conductor tracks, in particular made of metal, which are separate from one another. It is likewise contemplated for the conductor tracks to be in the form of metal conductor tracks of a circuit board or printed circuit board. The conductor tracks6can also be implemented in the form of a plug-type system, with the result that the connection of the contact sockets5can be changed. In this case, plug-type possibilities could be provided in one of the two plates or in both plates made of electrically insulating material, into which the conductor tracks6can be inserted during production of the cover1depending on the desired connection, with the result that covers with a different connection of the contact sockets5can be provided with relatively little effort. The cover1has a total of two connections13and14, one of which forms a positive pole and the other of which forms a negative pole of the electrically coupled storage cells2. That is to say, in the case of storage cells2connected in series with one another by means of the cover1, the connection13would be the positive pole of this series circuit and the connection14would be the negative pole of this series circuit.

FIG. 3is a schematic illustration of one development of the cover1fromFIG. 1, having a coolant or refrigerant flow adjacent to the conductor tracks. According to this development, the cover1can be provided with integrated cooling. As illustrated inFIG. 3, a cavity9is provided adjacent to the conductor tracks6which are provided between the contact sockets5. In the exemplary embodiment inFIG. 3, the contact sockets5and the conductor tracks6connecting the latter are formed in one piece, in particular monolithically. The cavity9is adapted to accommodate a cooling medium, wherein the cooling medium can directly touch the contact sockets5and the conductor tracks6, or an electrically insulating coating is formed in between, for example Teflon or a polymer coating. If the cooling medium directly touches the contact sockets5and the conductor tracks6, the cooling medium must be an electrically non-conductive cooling medium, for example an electrically non-conductive oil. The cooling medium is preferably a liquid coolant or refrigerant.

The cavity9may also be a space which is closed in a liquid-tight manner and is filled with a phase change material as the cooling medium. However, the cavity9is preferably provided with an inlet10and an outlet11and, apart from this inlet and outlet, is closed in a liquid-tight manner. The cavity9is incorporated in a closed cooling or refrigeration circuit by means of the inlet and outlet10,11.

FIG. 4is a schematic illustration of one development of the cover fromFIG. 1, having a coolant or refrigerant flow in the conductor tracks. In the exemplary embodiment illustrated inFIG. 4, the cavity9which is adapted to accommodate the cooling medium is formed by the interior of a pipe12which extends continuously from the inlet10to the outlet11. In the pipe12, the contact sockets15are formed by indentations in the pipe12in a form described in connection with the contact sockets5. In order to form the conductor tracks16or to produce the electrical conductivity of the conductor tracks16which connect selected contact sockets15to one another and in order to form the electrical conductivity of the contact sockets15, the sections of the pipe12which form the conductor tracks16and the contact sockets15are formed from electrical conductive material and the remaining sections of the pipe12are formed from electrically insulating material. However, the pipe12could also be continuously formed from electrically insulating material and could be covered or coated with an electrically conductive material in sections in order to produce the electrical conductivity of the conductor tracks16and the contact sockets15.

Whereas the invention has been illustrated and described in detail in the drawings and the preceding description, this illustration and description should be understood as illustrative or exemplary and not restrictive, and the intention is not to restrict the invention to the exemplary embodiments disclosed. The mere fact that particular features are mentioned in different dependent claims is not intended to indicate that a combination of these features also could not be advantageously used.