DE102018112351A1 - Battery system for a motor vehicle - Google Patents

Abstract

The invention relates to a battery system for a motor vehicle according to the preamble of claim 1, in particular a battery system (10) which is at least partially provided for the drive of a motor vehicle. The invention has for its object to provide a battery system (10) for a motor vehicle available, which has an improved thermal and at the same time tolerance-compensating connection of the arranged in these elements. In a battery system (10) for a motor vehicle according to the invention, which is arranged in a battery system housing, in which at least one cell module (16) with a battery system housing and at least one cooling system (22) for the cell module (16) are arranged, is in the battery system housing at least one, as gap filler (12) serving spacer fabric (14) is arranged, which has metallic elements and / or carbon fibers.

Description

The invention relates to a battery system for a motor vehicle according to the preamble of claim 1, in particular a battery system which is at least partially provided for the drive of a motor vehicle. Such battery systems usually have a nominal power (continuous power) of at least 12 kW in practice and / or give currents of at least 40 A. Such battery systems are - independently of or in addition to - often formed of several interconnected cell modules. Each cell module has a weight of at least 8 kg, at least 18 kg, at least 20 kg, at least 25 kg or at least 30 kg. Overall, battery systems according to the invention comprising a plurality of such cell modules frequently have a weight of at least 200 kg, at least 600 kg, at least 700 kg or at least 800 kg. The dimensions of battery systems according to the invention are in practice regularly such that at least one side of a cell module has a length of at least 10 cm, usually at least 25 cm, at least 30 cm, at least 40 cm or at least 50 cm. These lengths are often also valid for at least one other dimension, e.g. the width, or even for both other dimensions, i. the width and the height. Accordingly, these specifications also apply to the battery system with at least one such cell module. The battery system according to the invention and the cell modules arranged therein are therefore - in comparison to energy stores from other applications, such as e.g. Energy storage in home appliances - relatively large and heavy.

Out DE 10 2015 114 778 A1 is a spacer knitted fabric, which are formed from a first, conductive threads having flat knitted fabric, a second flat knitted fabric and the knitted fabric connecting spacer threads. In this case, the conductive threads on an electrically conductive coating. In the first knitted fabric, adjacent conductive filaments are connected to each other over their entire surface or in conductive strips running along a direction of production in direct electrical contact. Further, the conductive filaments are formed of a coated plastic multifilament yarn having a fineness of less than 250 dtex and knitted in the first knitted fabric layered over at least two wales, the conductive filaments being made conductive Coating less than 50 wt .-% is. As an application for this spacer knitted fabric, reference is made to a heatable cladding element in which a spacer knitted section is to be used with a covering layer having conductive threads. In this case, the cover layer should be arranged on the first, provided with the conductive threads knitted fabric, so that then below by the spacer threads and the second fabric layer, an advantageous insulating effect is ensured. Further applications and in particular an arrangement of the described spacer fabric in battery systems for a motor vehicle are in the DE 10 2015 114 778 A1 not described.

Out DE 10 2012 101 265 A1 For example, an energy storage device having at least one memory cell and a method for volume compression of electrode materials of such a memory cell are known. This energy storage device has at least one electrode arrangement as well as a volume compensation element reversibly compressible and / or decompressible in at least one orientation for compensating for a change in volume of the at least one electrode arrangement. This may be, for example, a three-dimensional textile in the manner of a spacer knit fabric, wherein the use of electrically conductive yarns and by means of such electrically conductive yarns electrically durchkontaktierter three-dimensional textiles is proposed. An arrangement of the described spacer fabric in connection with battery systems for a motor vehicle is not disclosed in this document.

Out EP 1 040 909 A1 is a press pad for use in laminating presses with two outer layers and an interposed, arranged in the direction of thickness elastic cushion layer known. In this case, the outer layers are formed by the two layers of a spacer textile with spacer layers connecting the layers, wherein at least a portion of the spacer threads is formed as Wärmeleitfäden.

In the production of as outlined above battery systems for motor vehicles and the cell modules used therein arise mainly due to cumulative manufacturing tolerances - in particular the nominal height of a cell module, the flatness of a cell module bottom, the nominal thickness of a housing surrounding the cell module and the flatness of the connection surface of the housing Cell module bottom - Gaps in the housing of a battery system whose size is variable and unknown prior to assembly.

The invention has for its object to provide a battery system for a motor vehicle available, which has an improved thermal and at the same time tolerance-compensating connection of the arranged in these elements.

The object is achieved according to the invention with the features of the independent claims. Other practical embodiments and Advantages of the invention are described in conjunction with the dependent claims.

In a battery system according to the invention for a motor vehicle, which is arranged in a battery system housing, in which at least one cell module with a battery system housing and at least one cooling system for the cell module are arranged, at least one spacer fabric serving as gap filler (filler) is arranged in the battery system housing, which comprises metallic elements and / or carbon fibers.

A battery system according to the invention has the advantage that, in particular because of the spacer fabric used as a gap filler (gap filler), it has a relatively low weight and the additional costs for the implementation of such a battery system are low. In addition, the battery system according to the invention has advantageous properties with respect to thermal conductivity. In addition, during assembly of a battery system according to the invention only small compression forces required to ensure proper and efficient functioning. Particular advantages may result if a spacer fabric is used which is produced in a textile process from long, endless fibers and has a plurality of geometrically differently arranged components. In particular, in this regard, the formation of a flat portion in the respective terminal areas, i. in particular on the upper side and underside, referred to the formation of an elastic portion between the terminal areas and the formation of a direct and directed as possible thermally conductive connection between the terminal areas, so that with the help of the spacer fabric, a good heat conducting connection can be made. Under a good heat-conducting connection in particular connections are understood to have a thermal conductivity of at least 3 W / mK. To achieve this, the spacer fabric preferably comprises fibers of metal and / or corresponding metallic wires. Alternatively or in addition, carbon fibers or hollow fiber textile structures may be used.

1. a) unmittelbar zwischen einer Wand eines Batteriesystemgehäuses und dem mindestens einen Kühlsystem,
2. b) unmittelbar zwischen dem Batteriesystemgehäuse und einer zwischen dem Batteriesystemgehäuse und dem mindestens einen Kühlsystem angeordneten Wärmetransportplatte und/oder
3. c) in unmittelbarem Kontakt zu einer in dem Batteriesystemgehäuse angeordneten, zu kühlenden elektrischen Leitung eines Batteriesystemelements

verwiesen. An den genannten Einsatzorten gemäß a), b) und c) erfindungsgemäßer Batteriesysteme müssen üblicherweise die größten Bauteiltoleranzen ausgeglichen werden, so dass mit einem Abstandsgewirke dieser Toleranzausgleich besonders effizient und funktional vorteilhaft realisiert und umgesetzt werden kann. Bei einem Batteriesystemelement kann es sich insbesondere um eine sogenannten Batterieanschlussbox handeln, die Leistungselektronik und andere elektrische Komponenten beinhaltet und üblicherweise zusammen mit mehreren Zellmodulen in einem Batteriesystemgehäuse angeordnet ist.With regard to the above-mentioned functional advantages when using a spacer knitted fabric in a battery system according to the invention, the use of a spacer knit fabric is particularly important

1. a) directly between a wall of a battery system housing and the at least one cooling system,
2. b) directly between the battery system housing and a arranged between the battery system housing and the at least one cooling system heat transfer plate and / or
3. c) in direct contact with an arranged in the battery system housing to be cooled electrical line of a battery system element

directed. At the above locations according to a), b) and c) battery systems according to the invention usually the largest component tolerances must be compensated, so that with a spacer knit this tolerance compensation can be implemented and implemented particularly efficient and functional advantageous. A battery system element may in particular be a so-called battery connection box, which contains power electronics and other electrical components and is usually arranged together with a plurality of cell modules in a battery system housing.

In a practical embodiment of a battery system according to the invention, the spacer knitted fabric is formed from a first flat knitted fabric layer, a second flat knitted fabric layer and spacer threads connecting the knitted fabric layers, with the metallic elements and / or carbon fibers direct thermally conductive contact between the first flat knitted fabric layer and the second flat knitted fabric layer is made. In this regard, reference is made in particular to the fact that the contact should extend to the respective outer sides of the first knitted fabric layer and the second knitted fabric layer in order to be able to produce a direct connection between the knitted spacer fabric and elements of the battery system which adjoin on the outside.

Even if the outer surfaces of the first flat knitted fabric layer and / or the second flat knitted fabric have an area fraction of metallic elements and / or carbon fibers of at least 5 percent, can by using a corresponding Abstandsgewirkes in a battery system according to the invention, compared to known from the prior art Gapfillern, advantageous thermal effect can be achieved. Preferably, said outer surfaces have an area fraction of at least 10 percent, at least 20 percent, at least 25 percent or even at least 50 percent. Said surface portion refers in particular to the outwardly directed surface, which serves as a connection region to another element, in particular to an element mentioned in the abovementioned points a), b) and c).

In a further practical embodiment of a battery system according to the invention, the spacer fabric has hollow fiber structures. The related advantages have already been referred to above.

In the first experiments in connection with a battery system according to the invention, it has been found that spacer fabrics with a height of between 0.5 mm and 10 mm are particularly suitable. Further preferred spacer fabrics are provided with a height between 0.5 mm and 6 mm and more preferably with a height between 0.5 mm and 4 mm.

The thermal conductivity of spacer fabrics in battery systems according to the invention can be increased in a particularly simple and cost-effective manner if the spacer fabric is completely or partially provided with a metallic coating. In particular, such a coating can be vapor-deposited or applied to a spacer fabric in any other suitable manner. In particular, reference is made in this connection to the possibility of using metallic elements and / or carbon fibers as spacer threads of the spacer knitted fabric and then applying a metallic coating to the first planar knitted layer and / or the second flat knitted fabric in such a way that a direct connection between the respective spacer threads and the first fabric layer and the second fabric layer is produced.

In a further practical embodiment, the spacer knitted fabric is completely or partially provided with a sheath. As such a wrapper, in particular, foil-like wrappings are understood which consist of a flexurally elastic foil material. In this regard, reference is made in particular to the use of metal foils and / or plastic films. Heat-conductive films, in particular those which have a thermal conductivity of at least 3 W / mK, are particularly preferred in this connection. Alternatively or in addition, insulating cladding can also be used to prevent electrical conductivity across the spacer fabric.

The thermal conductivity of a spacer knitted fabric of a battery system according to the invention can also be positively influenced by the fact that the threads of the spacer knitted fabric, at least partially wrapped with metallic or carbon-based additional elements, irrespective of whether they are the threads of the first knitted fabric, the second knitted fabric or spacer threads , In this regard, reference is made in particular to the use of strip-like elements, which are wound helically around the threads of a spacer knit and thus allow extensive contact with adjacent elements.

Finally, it should be pointed out that the spacer knitted fabric and / or a sheath which completely or partially surrounds the knitted spacer fabric can be provided with an adhesive coating. Such an adhesive coating is preferably also heat-conducting, with a heat-conducting coating in the present case, in particular, thermal conductivities of at least 1 W / mK being understood. Such an adhesive coating may, on the one hand, be used to connect a jacket to an optional jacket. In this case, the adhesive coating is provided on the inside of the cover between the cover and the spacer fabric. Alternatively or in addition, however, an adhesive coating can also be arranged on the outside of an envelope in order to cause the spacer fabric to adhere to another element and thus to improve the contact between a spacer knit and adjacent elements and, in particular, at changing distances to the other elements receive.

For the sake of completeness, it is once again referred to that a covering and an adhesive coating can be provided completely enclosing a spacer knitted fabric or only partially at areas in which the covering and / or the adhesive coating has an advantageous effect. In this regard, reference is made in particular to the possibility of effecting an electrical insulation by means of an enclosure, in order to prevent electrical conductivity across the spacer fabric.

• 1 eine schematische Darstellung eines Batteriesystems in einer ersten Ausführungsform,
• 2 eine schematische Darstellung eines Batteriesystems in einer weiteren Ausführungsform,
• 3 eine schematische Darstellung eines in einem erfindungsgemäßen Batteriesystem eingesetzten Abstandsgewirkes,
• 4 eine schematische Darstellung eines Ausschnitts eines Abstandsgewirkes, das in einem erfindungsgemäßen Batteriesystem eingesetzt ist,
• 5 einen Faden eines Abstandsgewirkes eines erfindungsgemäßen Batteriesystems mit einer Ummantelung, die aus einem flächigen Metallstreifen gebildet ist,
• 6 eine als Batteriesystem-Element dienende Batterieanschlussbox eines Batteriesystems mit einem als Lückenfüller dienenden Abstandsgewirke in einer Explosionsdarstellung und
• 7 eine exemplarische Schnittdarstellung durch die in 6 gezeigte Batterieanschlussbox mit montiertem Abstandsgewirke.

Further practical embodiments of the invention are described below in conjunction with the drawings. Show it:

• 1 a schematic representation of a battery system in a first embodiment,
• 2 a schematic representation of a battery system in a further embodiment,
• 3 a schematic representation of a spacer fabric used in a battery system according to the invention,
• 4 a schematic representation of a section of a spacer fabric, which is used in a battery system according to the invention,
• 5 a thread of a spacer knitted fabric of a battery system according to the invention with a sheath which is formed from a flat metal strip,
• 6 a serving as a battery system element battery terminal box of a battery system with a spacer fabric serving as a gap filler in an exploded view and
• 7 an exemplary sectional view through the in 6 shown battery connection box with mounted spacer fabric.

In the 1 and 2 are two different embodiments of battery systems according to the invention 10 shown, wherein in these and in all other figures for identical or at least functionally identical elements, the same reference numerals are used.

In the embodiment according to 1 is a schematic representation only, as a gap filler 12 serving spacer fabric 14 between one of one or more cell modules 16 existing cell module contact area 18 and a cooling system contact surface 20 a spaced-apart cooling system 22 arranged.

At the in 2 shown second embodiment is a gap filler 12 between a cell module contact surface 18 of one or more cell modules 16 and a first heat conducting plate contact surface 24 a heat conduction plate 26 intended. In addition, another is, as a gap filler 12 serving spacer fabric 14 between a second heat conducting plate contact surface 28 the heat conduction plate 26 and the cooling system contact surface 20 of the cooling system 22 intended.

3 shows an example of a spacer knitted fabric 14 which optionally comes with a wrapper 30 can be provided. The serving 30 can, as in 2 shown, the spacer knitted fabric 14 be formed partially enveloping or completely enveloping. As in 3 Moreover, it can be optionally illustrated between the spacer fabric 14 and the optional wrapper 30 an adhesive layer 32 be provided. In addition, alternatively or in addition to the outside of the optional enclosure 30 an adhesive coating 32 be provided.

4 schematically shows the structure of a section of a spacer knitted fabric 14 , The spacer fabric 14 is formed by a first flat knitted fabric layer 34 , a second flat knitted fabric 36 and the knit layers 34 . 36 connecting spacer threads 38 , How out 4 it can be seen, the spacer threads extend 38 in different directions transverse to the direction of extent of the first flat knitted fabric layer 34 and the second flat knitted fabric layer 36 , The first flat knitted fabric 34 and the second flat knitted fabric 36 are arranged parallel to each other in the embodiment shown. The spacer threads 38 can also, unlike in 4 shown to be arranged in an arc.

As in 4 is also apparent, are both in the first flat knitted fabric 34 as well as in the second flat fabric layer 36 on the one hand mesh 40 provided and beyond between the individual stitches 40 additionally running connecting threads 42 ,

Preferably, at least the spacer threads 38 made of a good thermal conductivity material, in particular with a heat transfer rate of at least 30 W / mK, or provided with a corresponding thermally conductive coating. Optionally, also the threads 44 the first fabric layer 34 , The strings 46 the second fabric layer 36 and / or the connecting threads 42 consist of correspondingly thermally conductive material or be provided with such a coating.

5 shows an example of a thread 48 in the form of a multifilament yarn, which is covered with a metallic strip 50 is wrapped helically. As in 5 shown results in each direction of the multifilament yarn 48 an outer surface that is at least 50 percent off the metallic strip 50 consists. Such a thread 48 can be beneficial as a thread 44 the first fabric layer 34 , as a thread 46 the second fabric layer 36 and / or as a spacer thread 38 be used. Particularly preferred is the use as a spacer thread 38 as well as a thread in the first knitted fabric 34 and the second fabric layer 36 ,

If a spacer knit 14 , as in 4 shown, exclusively of thermally conductive spacer threads 38 it may be advantageous if the respective outwardly facing surfaces, ie the outer surface 52 the first fabric layer 34 and the outer surface 54 the second fabric layer 36 completely or partially provided with a thermally conductive coating.

6 shows a so-called battery connection box 56 , which as a battery system element 58 Part of a battery system 10 may be in a battery system housing. In the battery connection box 56 In particular, electrical power modules, fuse elements and other electronic components are installed. These include five electrically conductive elements 60a . 60b . 60c . 60d . 60e acting as electrical wires 62 can be viewed. As in 6 can be a spacer knit 14 in a battery system according to the invention 10 be used advantageously by a spacer knitted fabric 14 in direct contact with one or more such electrical lines 62 is arranged. It is particularly advantageous in this context, if at least the areas of the spacer knitted fabric 14 which are in direct contact with the electrical lines 62 arrive, with an electrically insulating coating or a insulation foil 64 are provided. In 7 is in this respect exemplarily a spacer knitted fabric 14 with a first fabric layer 34 and a second knitted fabric layer 36 shown, with the outside surface 54 the second fabric layer 36 partially with an adhesive coating 32 is provided to the outside surface 54 the second fabric layer 36 with an insulation film 64 connect to. The spacer fabric 14 can be used as the top closure element of a battery connection box 56 serve or as gap fillers 12 between an unillustrated top cover of the battery connection box 56 and the electrical wires 62 to improve the heat transfer to a cooling system, not shown.

The features of the invention disclosed in the present description, in the drawings and in the claims may be essential both individually and in any desired combinations for the realization of the invention in its various embodiments. The invention may be varied within the scope of the claims and in consideration of the knowledge of the person skilled in the art.

LIST OF REFERENCE NUMBERS

10

battery system

12

Lückenfüller

14

spacer

16

cell module

18

Cell module contact area

20

Cooling system-contact surface

22

cooling system

24

first heat-conducting plate contact surface

26

heat conduction

28

second heat-conducting plate contact surface

30

wrapping

32

adhesive layer / coating

34

first flat knitted fabric

36

second flat knitted fabric

38

space area

40

mesh

42

connecting thread

44

Thread (the first fabric layer 34 )

46

Thread (the second fabric layer 36 )

48

Thread or multifilament yarn

50

metallic strip

52

Outer surface of the first fabric layer 34

54

Outer surface of the second knitted fabric layer 36

56

Batterieanschlussbox

58

Battery system element

60

electrically conductive element

62

electrical line

64

insulation foil

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102015114778 A1 [0002]
• DE 102012101265 A1 [0003]
• EP 1040909 A1 [0004]

Claims (10)

Battery system for a motor vehicle, which is arranged in a battery system housing, in which at least one cell module (16) with a battery system housing and at least one cooling system (22) for the cell module (16) are arranged, characterized in that in the battery system housing further at least one , is arranged as a gap filler (12) serving spacer fabric (14) having metallic elements and / or carbon fibers. Battery system according to the preceding claim, characterized in that the at least one spacer fabric (14) a) is arranged directly between a wall of a battery system housing and the at least one cooling system (b), b) directly between the battery system housing one between the battery system housing and the at least one Cooling system (22) arranged heat conducting plate (26) is arranged and / or c) is arranged in direct contact with a, arranged in the battery system housing to be cooled electrical line (62) of a battery system element. Battery system according to one of the preceding claims, characterized in that the spacer knitted fabric (14) of a first flat knitted fabric (34), a second flat knitted fabric (36) and the knitted fabric layers (34, 36) connecting spacer threads (38) is formed, wherein the metallic elements and / or carbon fibers direct, thermally conductive contact between the first flat knitted fabric layer (34) and the second flat knitted fabric layer (36) is made. Battery system according to one of the preceding claims, characterized in that the outer surfaces (52, 54) of the first flat knitted fabric layer (34) and / or the second flat knitted fabric layer (36) have a surface portion of metallic elements and / or carbon fibers of at least 5 percent. Battery system or cell module (16) according to one of the preceding claims, characterized in that the spacer knitted fabric (14) has hollow fiber structures. Battery system according to one of the preceding claims, characterized in that the spacer knitted fabric (14) has a height between 0.5 mm and 10 mm. Battery system according to one of the preceding claims, characterized in that the spacer knitted fabric (14) is completely or partially provided with a metallic coating (32). Battery system according to one of the preceding claims, characterized in that the spacer knitted fabric (14) is completely or partially provided with a sheath (30). Battery system according to the preceding claim, characterized in that the threads (42, 44, 44, 48) of the spacer knitted fabric (14) are at least partially wrapped with metallic or carbon-based additional elements. Battery system according to one of the preceding claims, characterized in that the spacer knitted fabric (14) and / or a sheath (30) completely or partially surrounding the knitted spacer fabric (14) is provided with an adhesive coating (32).

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