Abstract:
A battery includes at least one battery module that has several battery cells arranged next to each other on a support plate. The battery module is arranged with the support plate on a base plate of the battery or on a base plate of a lower unit of the battery. The support plate and the base plate are fixed together by at least one fixing system that includes at least two fixing elements engaging in each other. The first fixing element is arranged on the battery module and the second fixing element is arranged on the base plate. A motor vehicle includes the battery.

Description:
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2012/060459, filed on Jun. 4, 2012, which claims the benefit of priority to Serial No. DE 10 2011 077 349.5, filed on Jun. 10, 2011 in Germany, the disclosures of which are incorporated herein by reference in their entirety. 
     BACKGROUND 
     The present disclosure relates to a battery and to a motor vehicle comprising said battery, wherein the battery has at least one battery module which comprises a plurality of battery cells which are arranged on a support plate and at the same time the battery module is arranged by way of its support plate on a base plate of the battery or a base plate of a subunit of the battery, and the support plate and the base plate are connected to one another in a stationary manner by way of at least one fastening system. 
     It is known to design the basic structure of a battery such that in each case a plurality of battery cells are combined to form one battery module in the battery, and a plurality of battery modules are in turn arranged in a subunit. The battery is then formed from a plurality of said subunits. 
     In this case, said components are joined to form the assemblies usually by screw or rivet connections, as a result of which tools have to be used and an increased level of expenditure on installation is required for assembly. 
     SUMMARY 
     The disclosure provides a battery which has at least one battery module which comprises a plurality of battery cells which are arranged next to one another on a support plate. In this case, the battery module is arranged by way of its support plate on a base plate of the battery or a base plate of a subunit of the battery. The support plate and the base plate are connected to one another in a stationary manner by way of at least one fastening system. In this case, the fastening system has at least two fastening partners which latch one into the other, wherein the first fastening partner is arranged on the battery module, and the second fastening partner is arranged on the base plate. In this case, the battery is preferably a lithium-ion battery. 
     In this way, it is advantageously possible to assemble the battery quickly, simply and reliably by virtue of the battery module latching into the base plate. In addition, accessibility is only required from a single direction, this being advantageous for assembly. 
     Owing to the contour of the fastening partners, at least one of the fastening partners is forced to elastically deform when the battery module and the base plate are joined, said fastening partner springing back out of said elastic deformation during latching-in and engaging behind the other fastening partner. As a result, advantageously, no additional tool is required for mounting the battery module on the base plate. 
     Furthermore, a clear position of the battery module on the base plate of the battery or the base plate of a subunit of the battery is advantageously prespecified by way of the fastening system. As a result, the assembly process for the battery according to the disclosure can be easily incorporated into an automated process. 
     In this application, the first fastening partner is defined in that it is arranged on the battery module, and the second fastening partner is defined in that it is arranged on the base plate. 
     In a preferred refinement of the disclosure, it is provided that at least one interlocking connection in a direction perpendicular to the base plate is established by the two fastening partners. 
     In this way, the battery module is prevented from lifting off from the base plate immediately after the battery module is mounted on the base plate. 
     In a further preferred refinement of the disclosure, it is provided that the first fastening partner is arranged on the support plate of the battery module. 
     Since the support plate of the battery module provides a relatively large surface area and is mounted on the base plate of the battery or on the base plate of a subunit of the battery, a variety of positioning options are possible for the arrangement of the first fastening partner on the support plate. This advantageously provides a relatively large amount of room for manoeuvre in respect of design when packaging the battery. 
     As an alternative to the arrangement of the first fastening partner on the support plate of the battery module, it is provided that the first fastening partner is arranged on a pressure plate of the battery module, said pressure plate being arranged next to an outer one of the battery cells. In this case, a pressure plate is preferably arranged in front of the first battery cell and behind the last battery cell of the battery module in each case. 
     Given this configuration, the fastening points are arranged on the outer edges of the base surface of the battery module. Therefore, a distance between the fastening systems which is as large as possible and therefore more efficient fastening can advantageously be achieved. 
     In a further preferred refinement of the disclosure, it is provided that the second fastening partner is formed by a cutout in the base plate and an area, which borders the cutout, of the base plate. In this case, the first fastening partner is preferably a spring arm which projects into the cutout and engages behind that area of the base plate which borders the cutout. 
     A cutout advantageously constitutes the most simple and most cost-effective refinement with which an undercut is generated, said undercut allowing the other fastening partner to latch-in. In this case, the cutout is preferably a hole, in particular a blind hole. 
     In this case, the cutout is preferably arranged in the base plate, beneath the battery module. 
     This advantageously has the result that no additional space is required within the battery for the fastening system. 
     In a preferred refinement, it is provided that the first fastening partner is a projection, and the second fastening partner is a spring arm which engages behind the projection. 
     In this way, a second fastening partner is created, said second fastening partner projecting out of the basic shape of the support plate. The core of the support plate remains untouched when the fastening system is designed in this way. Therefore, it is advantageously possible to conduct systems, lines, in particular cooling lines or the like, through the support plate. 
     Therefore, in a further preferred refinement of the disclosure, it is provided that the base plate dissipates heat, that is to say is a cooling plate. 
     Given the configuration of the base plate as a cooling plate, it is advantageously easier to control the temperature of the battery module. 
     In a further preferred refinement of the disclosure, it is provided that an intermediate layer which applies a pretensioning force between the battery module and the base plate is arranged between the battery module and the base plate. 
     In this way, the fastening system is advantageously better secured against the fastening partners becoming detached from one another. 
     In a further preferred refinement of the disclosure, it is provided that the first fastening partner is integrally formed with the support plate or the pressure plate and/or the second fastening partner is integrally formed with the base plate. 
     In this way, the battery according to the disclosure is advantageously constructed from fewer individual parts. 
     The disclosure further provides a motor vehicle comprising the battery according to the disclosure in the abovementioned refinements, wherein the battery is connected to a drive system of the motor vehicle. The advantages of the battery according to the disclosure as a component are therefore also of benefit to the motor vehicle as an assembly. 
     Advantageous developments of the disclosure are specified in the dependent claims and discussed in the description. 
     In this application, the term “battery” also includes battery systems, accumulators, accumulator batteries, accumulator systems, in particular lithium-ion systems or lithium-ion polymer systems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will be explained in greater detail with reference to the drawings and the following description. In the drawings: 
         FIG. 1  shows the basic structure of a battery according to the prior art, 
         FIG. 2  shows a battery module according to the prior art, 
         FIG. 3  shows a schematic diagram of an embodiment of a battery module of a battery according to the disclosure, 
         FIG. 4  shows a schematic diagram of a further embodiment of the battery module of the battery according to the disclosure, 
         FIG. 5  shows a cross section through a pressure plate of a battery module of a battery according to the disclosure, 
         FIG. 6  shows a schematic diagram of a further embodiment of the battery module of the battery according to the disclosure, 
         FIG. 7  shows a schematic diagram of a further embodiment of the battery module of the battery according to the disclosure, 
         FIG. 8  shows a support plate with fastening elements, and 
         FIG. 9  shows a pressure plate with fastening elements. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows, by way of example and in a non-limiting manner, the basic structure of a battery  10  according to the prior art. In principle, the battery  10  according to the disclosure has the same basic structure. A plurality of battery cells  16  are in each case combined to form one battery module  14  in the battery  10 . A plurality of battery modules  14  are arranged in a subunit  12  in each case. And a plurality of subunits  12  form the battery  10  in this case. 
     It is also possible for the battery  10  to comprise only a single subunit  12  or only a single battery module  14 . 
       FIG. 2  shows, by way of example and in a non-limiting manner, a battery module  14  according to the prior art. The battery module  14  of the battery  10  according to the disclosure is based on this design. In the depicted variant, the battery module  14  has six battery cells  16 . There may also be more or less than six battery cells  16  per battery module  14 . The number of battery cells  16  depends on the required power and energy parameters of the battery module  14  and the power and energy parameters of the individual battery cells  16 . 
     The battery cells  16  each have a substantially prismatic main body, preferably a substantially cuboidal main body, and are arranged next to one another jointly on a support plate  18 . As a result, the battery module  14  likewise has a substantially prismatic basic shape, preferably a substantially cuboidal basic shape. 
     In this case, the battery cells  16  are preferably mounted on the support plate  18  by way of their bottom face, that is to say the face of the body which is opposite the face of the body on which the terminals  34  are located. 
     In order to hold the individual battery cells  16  together, said battery cells are surrounded by at least one tensioning strap  22 . In order that the outer battery cells  16 , that is to say those which adjoin a further battery cell  16  only on one side, are not subject to excessive loading in the process, pressure plates  20  are preferably provided on the end faces of the battery cell  14 . The pressure plates  20  distribute forces which are exerted by the tensioning strap  22  over a large area of the outer battery cells  16 . 
     Heat-conducting metal sheets are optionally arranged between the individual battery cells  16  in order to better thermally interlink the individual battery cells  16 . 
       FIG. 3  shows, by way of example and in a non-limiting manner, a schematic diagram of one embodiment of a battery module  14  of the battery  10  according to the disclosure. Said figure shows a cross section parallel to an end face of the battery module  14 . 
     Said figure shows the battery module  14  comprising a battery cell  16  and a support plate  18  on a base plate  24 . In this case, the base plate  24  can be part of a subunit  12  of the battery  10  or part of the battery  10  itself. 
     In a refinement according to the disclosure, the battery module  14  and the base plate  24  have fastening systems  26 . Two fastening systems  26  which are arranged in a mirror-inverted manner in relation to one another are depicted. 
     According to the disclosure, at least one fastening system  26  is provided. According to the disclosure, the arrangement of further fastening systems  26  is provided depending on the size and mass of the battery module  14 . Said fastening systems can also be arranged offset and/or at an angle in relation to one another. According to the disclosure, it is also feasible for different embodiments of fastening systems  26  to be present at the same time. 
     The fastening systems  26  shown in  FIG. 3  each have two fastening partners, a first fastening partner  30  and a second fastening partner  32 . In this case, the first fastening partner  30  is defined in this application in that it is arranged on the battery module  14 , and the second fastening partner  32  is defined in that it is arranged on the base plate  24 . 
     The design of the depicted fastening partners  30  and  32  is merely exemplary. In  FIG. 3 , the first fastening partners  30  are each formed by a spring arm with an undercut. And the second fastening partners  32  are formed by a respective cutout  36  and an area, which adjoins the cutout, of the base plate  24  in this case. 
     The spring arm has a substantially elongate design which can be elastically deformed by bending. At its free end, the spring arm is provided with a beveled area by means of which this elastic bending is caused when the contour of the second fastening partner  32  is moved over. Behind the bevels, the spring arm has an undercut. When the fastening partners  30  and  32  latch-in, said undercut, together with an area of the second fastening partner  32 , establishes an interlocking connection counter to the mounting direction. This prevents the battery module  14  from lifting off from the base plate  24 . 
     When the battery module  14  is joined to the base plate  24 , the spring arms are pushed away from the contour of the base plate  24 , that is to say the cutouts  36 , and spring back into their normal, undeformed position after passing the cutouts  36 . As a result, the undercut of the spring arms engages behind the base plate  24 . The respective spring arm is additionally blocked by the wall of the cutout  36  at least in a transverse direction in relation to the mounting direction. The fastening systems  26  are preferably oriented such that the various fastening systems  26  block the first fastening partners  30  in different transverse directions. 
     In a modification to the embodiment which is shown in  FIG. 3 , the cutouts  36  can also be arranged at the edge of the base plate  24 . In addition, a design of the cutouts  36  as blind holes is also possible, said blind holes having a depth which is less than the thickness of the base plate  24 . Therefore, the cutout  36  does not extend as far as the bottom face of the base plate  24 . The blind hole then itself has an undercut in the interior, it being possible for the first fastening partner  30  to latch into said undercut. 
     Depending on the embodiment of the cutout  36 , the height of the first fastening partner  30  is such that the battery module  14  rests on the base plate  24  with a defined force. To this end, an intermediate layer  28  may be arranged between the battery module  14  and the base plate  24 . 
       FIG. 4  shows, by way of example and in a non-limiting manner, a schematic diagram of a further embodiment of the battery module  14  of the battery  10  according to the disclosure. Said figure shows a cross section parallel to an end face of the battery module  14 . 
     In addition to the refinement shown in  FIG. 3 , the variant of  FIG. 4  has an intermediate layer  28  which is arranged between the support plate  18  and the base plate  24 . According to the disclosure, the intermediate layer  28  is optionally provided. 
     The intermediate layer  28  exerts a defined pretensioning force on the battery module  14  and the base plate  24  in the mounted state. In this case, the intermediate layer  28  has elastic deformation properties. This is indicated by the undulating illustration in  FIG. 4 . The actual design of the intermediate layer  28  can differ from that which is illustrated. 
       FIG. 5  shows, by way of example and in a non-limiting manner, a cross section through a pressure plate  20  of a battery according to the disclosure. The pressure plate  20  has an integrated first fastening partner  30 . The number and the arrangement of fastening partners  30  can vary in this case; said number of fastening partners  30  must not correspond to the number of second fastening partners  32  of the base plate  24  (not depicted here) so that several options in respect of the location of a means for fixing the battery module  14  on the base plate  24  are provided. 
     In  FIG. 5 , the first fastening partner  30  is a spring arm by way of example. In  FIG. 9 , the two first fastening partners  30  of the pressure plate  20  are designed as projections by way of example. According to the disclosure, the pressure plate  20  and the first fastening partner  30  are preferably of integral design. In accordance with the shape of the first fastening partners  30 , the second fastening partners  32  are designed so as to correspond to the first fastening partners  30 , so that latching-in in a defined position is possible. 
     Therefore,  FIG. 6  shows, by way of example and in a non-limiting manner, a schematic diagram of an embodiment of the battery module  14  of a battery  10  according to the disclosure in which the first fastening means  30  are likewise formed as projections. In this case, they are formed on the support plate  18  of the battery module  14 , in contrast to  FIG. 9 . Said  FIG. 6  shows a cross section parallel to an end face of the battery module  14 . 
     The battery module  14  comprising a battery cell  16  and a support plate  18  on a base plate  24  is shown in said  FIG. 6 . In this case, the base plate  24  can be part of a subunit  12  of the battery  10  or part of the battery  10  itself. 
     In a refinement according to the disclosure, the battery module  14  and the base plate  24  have fastening systems  26 . Two fastening systems  26  which are arranged in a mirror-inverted manner in relation to one another are depicted. 
     The design of the fastening partners  30  and  32  which are illustrated in  FIG. 6  is merely exemplary. In  FIG. 6 , the first fastening partners  30  are each formed by a projection from the support plate  18 . The projections each have a rising slope and an undercut. In this case, the second fastening partners  32  are each formed by a spring arm. 
     When the battery module  14  is joined to the base plate  24 , the spring arms are pushed away from the contour of the support plate  18 , that is to say the rising slopes, and spring back into their normal, undeformed position after passing the rising slopes. As a result, the undercut of the spring arms in each case engages behind the support plate  18 . The undercut of the spring arm and the undercut of the projection from the support plate  18  therefore form an interlocking connection in each case. 
       FIG. 7  shows, by way of example and in a non-limiting manner, a schematic diagram of a further embodiment of the battery module  14  of the battery  10  according to the disclosure. Said figure shows a cross section parallel to an end face of the battery module  14 . 
     In addition to the refinement which is shown in  FIG. 6 , the variant of  FIG. 7  has an intermediate layer  28  which is arranged between the support plate  18  and the base plate  24 , in line with  FIG. 4 . 
       FIG. 8  shows, by way of example and in a non-limiting manner, a support plate  18  of a battery  10  according to the disclosure. In this case, the support plate  18  has first fastening partners  30  which are designed as projections. According to the disclosure, the projections are preferably integrally formed with the support plate  18 .