Abstract
An energy storage device for a motor vehicle includes a plurality of round cells for electrochemical storage of energy and multiple retaining frames for retaining the round cells. The round cells are secured to opposing retaining frames by their ends. Cell connectors are provided on the retaining frames, which electrically contact the round cells arranged between the retaining frames from the outer sides.
Claims
1.-15. (canceled)
16. An energy storage device for a motor vehicle, the energy storage device comprising: a plurality of round cells for electrochemical storage of energy; and a plurality of retaining frames for retaining the round cells; wherein: the round cells are secured to opposing retaining frames by ends of the round cells; cell connectors are provided on the retaining frames; and the cell connectors electrically contact the round cells arranged between the retaining frames from outer sides of the retaining frames.
17. The energy storage device according to claim 16, wherein the retaining frames comprise recesses in which the ends of the round cells are accommodated.
18. The energy storage device according to claim 17, wherein the retaining frames further comprise adhesive channels through which, in an assembled state of the round cells, adhesive is introducible introduced into the recesses in order to secure the round cells.
19. The energy storage device according to claim 17, wherein the ends of the round cells are secured in the recesses by way of at least one of a form-fitting connection or a force-fitting connection.
20. The energy storage device according to claim 19, wherein the form-fitting connection is pressing-in.
21. The energy storage device according to claim 16, wherein: each retaining frame is composed of multiple retaining frame elements, and each retaining frame element comprises at least two recesses.
22. The energy storage device according to claim 21, wherein immediately adjacent retaining frame elements are connected to one another via a form-fitting connection.
23. The energy storage device according to claim 22, wherein the form-fitting connection is a latching connection.
24. The energy storage device according to claim 21, wherein: the retaining frame is formed from a plurality of retaining frame elements that are secured to one another; and the retaining frame elements differ in terms of at least one of a contour or a number of recesses to better use an installation space.
25. The energy storage device according to claim 21, wherein at least one of the retaining frames or the retaining frame elements are produced from an electrically insulating material.
26. The energy storage device according to claim 16, wherein at least one of: the cell connectors of a retaining frame are covered from an outer side with an insulation layer; or the cell connectors of the retaining frame are cast on the outer side by way of electrically insulating casting compound.
27. The energy storage device according to claim 26, wherein the insulation layer is an insulation film or an insulation plate.
28. The energy storage device according to claim 16, wherein: the round cells are arranged in layers; cooling elements for cooling the round cells are provided between at least two of the layers; and the cooling elements are of at least partly undulating design.
29. The energy storage device according to claim 28, wherein at least one of: an intermediate space between the round cells and the cooling elements is filled at least partly with a thermally conductive material; or at least one of a top side formed by the plurality of round cells, a bottom side formed by the plurality of round cells, or intermediate spaces between the round cells are provided with a flame-retardant medium.
30. The energy storage device according to claim 16, wherein: the round cells in their installed position run substantially parallel to a vehicle transverse axis; the round cells are arranged in multiple layers within a storage housing in a direction of a vehicle vertical axis; and a number of the layers varies in a direction of a vehicle longitudinal axis.
31. The energy storage device according to claim 16, wherein a length-to-diameter ratio of the round cells has a value between 5 and 30.
32. The energy storage device according to claim 31, wherein the value is between 7 and 15.
33. The energy storage device according to claim 32, wherein the value is between 9 and 11.
34. The energy storage device according to claim 30, wherein fewer layers are arranged in at least one of foot regions of the storage housing, the foot regions adjoining a front or rear footwell, than in a seat region of the storage housing, the seat region adjoining at least one of the front seats or the rear seats.
35. A motor vehicle comprising the energy storage device according to claim 16.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] FIG. 1 shows a schematic perspective view of an energy store according to an exemplary embodiment of the invention.
[0063] FIG. 2 shows a schematic section of a longitudinal section through a motor vehicle according to the technology disclosed here.
[0064] FIG. 3 shows a schematic section of a longitudinal section through a motor vehicle according to a further exemplary embodiment of the technology disclosed here.
[0065] FIG. 4 shows a schematic cross-sectional view along the line IV-IV according to FIG. 5.
[0066] FIG. 5 shows a schematic cross-sectional view along the line V-V of FIG. 4.
[0067] FIG. 6 shows a schematic cross-sectional view along the line VI-VI of FIG. 4.
[0068] FIG. 7 shows a schematic cross-sectional view along the line VII-VII of FIG. 4.
[0069] FIG. 8 shows a schematic illustration of the retaining frames 200, the retaining frame elements 230, 231 and the cell connectors 220.
[0070] FIG. 9 shows an enlarged schematic illustration of retaining frame elements 230 in a further configuration.
[0071] FIG. 10 shows an enlarged schematic illustration of round cells 120 and a cell connector 220.
DETAILED DESCRIPTION OF THE DRAWINGS
[0072] FIG. 2 shows a schematic section of a longitudinal section through a motor vehicle according to the technology disclosed here. The storage cells of the energy storage device 100 are configured here as round cells 120, which are accommodated in the storage housing 110 in a manner organized in layers. The round cells 120 are arranged here substantially parallel to the vehicle transverse axis Y. The bottom layer of round cells extends here from the front foot region FV of the storage housing 110 to the rear seat region SH of the storage housing 100 counter to the direction of the vehicle longitudinal axis X. The rear seat region SH is arranged here underneath the rear bench seat. The number of layers varies in the direction of the vehicle longitudinal axis X in order to thus utilize the installation space in optimum fashion. The height of the individual round cells 120 or the layers in the direction of the vehicle vertical axis Z results here from the maximum external diameter of the round cells 120. Since the maximum external diameter of the round cells 120 is relatively small in comparison to previously known prismatic cells, the installation space that is present in the direction of the vehicle vertical axis Z can be utilized much better here. The housing contour KG is also advantageously adapted here to the internal contour KI of the passenger cabin 150 (cf. also FIG. 5). For the purpose of better use of the installation space, the immediately adjacent round cells 120 are arranged spaced further apart from one another in the rear seat region SH or first region B1 than immediately adjacently of the round cells 120 in the front seat region SV or second region B2. By way of these measures, the round cells 120 of the immediately adjacent second layer can penetrate deeper into the intermediate regions of the first or bottom layer in the first region B1, as a result of which a total of three layers can be integrated in this first region. Without these measures, only two layers would be able to be arranged in this installation space. Two cell modules ZM1, ZM2, which each have two retaining frames 200 (cf. FIG. 4), are provided here in the energy storage device 100. The cell modules ZM1, ZM2 are arranged here parallel to one another and have the same contour in the direction of the vehicle vertical axis Z.
[0073] FIG. 3 shows a schematic section of a longitudinal section through a motor vehicle according to a further exemplary embodiment of the technology disclosed here. In the following description of the alternative exemplary embodiment illustrated in FIG. 3, the same reference signs are used for features that are identical and/or at least comparable in terms of their configuration and/or mode of operation in comparison to the first exemplary embodiment illustrated in FIG. 2. If these features are not explained again in detail, the configuration and/or mode of operation thereof corresponds to the configuration and/or mode of operation of the features already described above. The configuration according to FIG. 3 differs from the previous configuration in that the internal contour KI and the housing contour KG of the energy storage device 100 in the region of the rear seat bench has been changed. The energy storage device 100 here has more installation space overall in the rear seat region in the direction of the vehicle vertical axis Z. Consequently, there are further layers here in comparison to the configuration according to FIG. 2, of which the top three layers have round cells 120 that are spaced further apart in the direction of the vehicle longitudinal axis X for better adjustment to the overall height.
[0074] FIG. 5 shows a schematic cross-sectional view along the line V-V of FIG. 4. The figure shows the energy storage device 100 of FIG. 2 and the internal contour KI of the motor vehicle. The rest of the components of the motor vehicle have been omitted for simplification. FIG. 5 depicts the first intermediate region ZB, which is formed from immediately adjacent round cells 120 of the bottom layer L1.
[0075] FIG. 4 shows a schematic cross-sectional view along the line IV-IV according to FIG. 5. The plurality of round cells 120 are arranged parallel to the vehicle transverse axis Y. The round cells 120 have a length-to-diameter ratio of approximately 10. The cooling elements 140 are arranged here perpendicular to the round cells 120 and parallel to the vehicle longitudinal direction X. The cooling elements 140 are of strip-like design. The width of the cooling elements 140 is smaller than the length of the round cells 120 by a multiple. The cooling elements 140 can be of a substantially undulating design in a cross section perpendicular to the vehicle transverse axis Y. The cooling elements 140 have been omitted in the other views and cross sections for simplification. The adhesive, which can be applied here between the two cooling elements 140, is not illustrated here or in the other figures. The adhesive is expediently set up to connect the round cells 120 of a layer L1, L2, L3, L4 to one another. Likewise not shown here are the undulating position elements, which in one configuration position the bottom layer and the base of the housing relative to one another. In the configuration shown here, the electrical cell terminals of the round cells 120 are provided on the outer edge of the bottom layer L1. The round cells 120 preferably each have the degassing opening (not shown here) only at the toward the outer edge or toward the outer longitudinal support of the motor vehicle. In the embodiment illustrated here, in each case two bottom layers L1 are arranged behind one another in the direction of the vehicle transverse axis Y. The two bottom layers L1 are provided parallel to one another. It is likewise conceivable that only one bottom layer L1 or three bottom layers L1 are provided in the storage housing. It is likewise conceivable that, instead of two round cell stacks, only one round cell stack with correspondingly longer round cells 120 or three round cell stacks with correspondingly shorter round cells 120 is/are provided.
[0076] FIG. 1 shows a perspective view of a cell module ZM1 according to the technology disclosed here. The cell module ZM1 comprises a plurality of round cells 120, which are arranged parallel to one another. The plurality of round cells 120 are retained here by two retaining frames 200. The retaining frames 200 are each arranged laterally from the round cells 120. Each end of the round cells 120 is respectively accommodated in one of the two retaining frames 200. The two retaining frames 200 fix the round cells 120 here. The cell module ZM1 is likewise divided here into foot regions FV, FH and seat regions SV, SH. Here, only one layer of round cells 120 is provided in the rear foot region FH. The retaining frame elements 231, 231 installed here accordingly have a flat, single-layer contour in the direction of the vehicle vertical axis Z. Somewhat more space for the energy storage device 100 is provided here in the front foot region FV. Respective structurally identical retaining frame elements 230, which each have a two-layer construction, are accordingly installed here. The cell module ZM1 further comprises two cooling elements 140, which are arranged between the first layer L1 and the second layer L2. The terminals 146 of the cooling elements 140 are located here on the front side of the cell module ZM1.
[0077] FIG. 6 shows a schematic cross-sectional view of two retaining frames 200. The contour of the retaining frame 200 corresponds to the housing contour GK of the energy storage device 100. The retaining frames 200 have a length-to-height ratio of approximately 20. In the installed position, the length LH runs here in the direction of the vehicle longitudinal axis X. The height HH here runs parallel to the vehicle vertical axis Z. Each retaining frame 200 comprises a plurality of recesses 222, in which the round cells 120 (not shown here) are inserted. The front retaining frame 200 also shows the cell connectors 220. The cell connectors 220 are configured such that they have the lowest possible electrical resistance. The shape of the cell connectors 220 is determined by the installation situation and the interconnection of the round cells 120. A preferred configuration is shown in FIG. 10. In principle, different interconnection logic systems (nP interconnection) are conceivable. The retaining frame 200 or the retaining frame elements 230 disclosed here may be (an) injection-molded part(s), for example.
[0078] FIG. 7 shows a perspective view of a cell module ZM1 of modular construction. The retaining frame 200 here comprises a plurality of retaining frame elements 230, of which two retaining frame elements 230 are shown by way of example. Four round cells 120 are accommodated in each retaining frame element 230 here. The retaining frame element 230 is of two-layered construction. The round cells 120 are thus arranged in two layers lying one above the other. In the example shown here, the cell connector 220 connects a respective round cell 120 of the top layer to a round cell 120 of the bottom layer. The retaining frame elements 230 are connected to one another in a form-fitting manner here in each case via a clip connection (not shown). The connection region (shown using dashes) for connecting two adjacent retaining elements 230 is of stepped design here. A self-centering connection region could advantageously also be provided, for example with a V-shaped contour. The connection region is designed here in such a way that individual retaining frame elements can be secured to one another by way of sliding in the direction of the longitudinal axis of the round cells. Therefore, the following can advantageously be connected to one another at the same time by moving: [0079] iii) the individual adjacent retaining frame elements 230, and [0080] iv) the ends of the round cells 120 accommodated in the respective retaining frame element 230 and the respective retaining frame element 230.
[0081] A plurality of retaining frame elements 230, which are connected behind one another and connected to one another, are expanded here to form a retaining frame 200, which in the installed position extends substantially along the vehicle longitudinal axis X. By way of example, a retaining frame 200 according to FIG. 6 can comprise the retaining frame elements 230 shown here.
[0082] The manufacture of the cell module ZM1 particularly preferably makes provision for first of all the retaining elements 230 to be populated with round cells 120 to form a submodule and the cell module ZM1 is subsequently put together by connecting the individual retaining elements 230. In particular, provision can be made for the same retaining frame element 230 to be set up to be used for cell modules with retaining frames 200 of different length. Each submodule comprises corresponding terminals for the cooling elements 140 and the electrical contacts (cell monitoring system, cell connector, etc.). In another configuration, the cooling system is provided only after the submodule has been assembled. In a further configuration, the retaining frames 200 are first of all produced from individual retaining frame elements 230, 231 and the cell module is subsequently manufactured using the preassembled retaining frames 200. It is expediently possible to preassemble one of the retaining frames 200, in which the round cells 200 (with or without an intermediate layer of the cooling element(s) 140) are first of all inserted before the opposing second retaining frame 200 is subsequently successively manufactured by way of secured individual retaining frame elements 230. This method is also applicable to differently configured energy storage devices and other exemplary embodiments. Therefore, advantageously only the few round cells 120 that are accommodated in the retaining frame element 230 that is to be secured have to be positioned exactly. This can simplify the assembly.
[0083] FIG. 8 shows a schematic cross-sectional view at various points of the cell module ZM1.
[0084] The left-hand part (a) of FIG. 8 shows a section as may be provided, for example, in the rear foot region FH of FIG. 1. The, in this case undulating, cooling element 140 is provided here at the top. The round cells 120 contact the undulating cooling element 140 on the bottom side thereof. The round cells 120 can therefore output the heat to the cooling element 140 well. The thermally conductive material 142 can also be arranged here between the round cells 120 and the cooling element 140. The heat can therefore be transmitted particularly well to the cooling element 140. The thermally conductive material 142 may be, for example, a silicone with fillers for increasing the thermal conductivity. A flame-retardant medium 144, for example an anti-propagation paste (for example thermal insulation, heat-absorbing layer, or a fire-extinguishing medium) could be provided as further protection for the bottom side U. The flame-retardant medium 144 is provided equally on the top side of the cooling element 140 and between the round cells.
[0085] The central part (b) of FIG. 8 shows a section as may be provided, for example, in the front foot region FV of FIG. 1. Two layers L1, L2 of round cells 120 are provided here, the layers being arranged above one another in the direction of the vehicle vertical axis Z. The cooling element 140 is arranged here in the intermediate layer between the two layers L1, L2. In a similar manner to in part (a), a thermally conductive material 142 is provided here toward the cooling element 140. The flame-retardant medium 144 is again provided here towards the top side 0 and towards the bottom side U as well as between the round cells.
[0086] The right-hand part (c) of FIG. 8 shows a section as can be provided, for example, in the front seat region SV of FIG. 1. Three layers L1, L2, L3 are arranged in this region one above the other. A respective cooling element 140 is arranged between two layers. For further protection from propagation, provision may be made for the flame-retardant medium 144 to also be inserted within the layer construction. A part of the housing 100 is additionally shown in this cross-sectional view.
[0087] FIG. 9 shows a schematic cross-sectional view of the cell module ZM1 along the sectional line S-S of FIG. 1. The undulating cooling element 140 is configured here in the front seat region SV in such a way that the cooling element 140 does not run exclusively here between the first layer 1 and the second layer L2. The cooling element 140 runs in the three layers L1, L2, L3 arranged one above the other along the longitudinal direction of the layers or vehicle longitudinal direction X alternately between the first layer L1 and the second L2 and the second layer L2 and the third layer L3. In this region, the cooling element 140 loops around adjacent round cells 120 of the second layer L2 in the longitudinal direction. It is therefore particularly simple to cool the three layers L 1, L2, L3 using a cooling element 140. Multiple cooling elements 140 can preferably be arranged next to one another in the transverse direction (that is to say in the longitudinal direction of the round cells 120).
[0088] FIG. 10 shows an enlarged schematic illustration of round cells 120 and a cell connector 220. Such a cell connector can be installed in each of the energy storage devices disclosed here. However, other geometries may also be conceivable. Along the main direction (illustrated as an arrow) of the flow of current—that is to say between the different poles (negative to positive, positive to negative) of the contacted round cells 120 (or here in the direction of the longitudinal axis of the retaining frames or of the vehicle longitudinal axis), the cell connector 220 has a greater cross section QH than perpendicular to this cross section QN—that is to say between the same poles (negative to negative, positive to positive) or in the direction of the vehicle vertical axis Z.
[0089] The cross-sectional ratio of the cross-sectional area in the main direction to the cross-sectional area perpendicular thereto preferably has a value of at least 2 or at least 5 or at least 10. The cross-sectional ratio is the quotient from the cross-sectional area in the main direction as the numerator and the cross-sectional area perpendicular to the cross-sectional area in the main direction as the denominator.
[0090] The resistance in the main direction through which current flows is thus advantageously reduced, and material and installation space can be saved in the transverse direction. Forces resulting from thermal expansion can also be reduced. This installation space can preferably be used for the retaining frame.
[0091] The preceding description of the present invention is used only for illustrative purposes and not for the purpose of restricting the invention. Within the scope of the invention, various changes and modifications are possible without departing from the scope of the invention and the equivalents thereof. Even if the energy storage device is shown here with round cells, the technology disclosed here can equally be applied to other cell geometries that expediently have the cross section-to-length ratios disclosed here.
