Motor vehicle with traction battery module

Abstract

The invention relates to a motor vehicle (100) having a traction battery module (10), the traction battery module having a tightly sealed module housing (20), in which at least one cell stack pair (600) is accommodated, each cell stack pair consisting of a left cell stack (60) and a right cell stack (60'). The traction battery module (10) is arranged on a vehicle floor (102) and extends symmetrically in a vehicle transverse direction (X) relative to a vehicle center (M). The traction battery module has a bottom wall (26) in a horizontal plane. In the module housing (20) located in the vehicle center (M) and relative to the vehicle transverse direction (X), a gas space (66) is formed between the left cell stack (60) and the right cell stack (66'), and the module bottom wall (26) has a venting element (30) in the region of the gas space (66) in the vehicle center.

Description

Technical Field

[0001] The invention relates to a motor vehicle having a traction battery module which feeds electrical energy to a traction motor of the motor vehicle. Background Art

[0002] A motor vehicle traction battery module has a tightly sealed module housing, in which generally a plurality of cell stacks, each consisting of a plurality of battery cells, are accommodated in a gas-tight manner. In the event of a thermal event, very hot gases can suddenly escape from the cell stack, which must be directed out of the module housing in a targeted manner. DE 10 2018 221 990 A1 discloses a traction battery having a plurality of battery cells in a battery housing, which has a lateral venting element in the form of a rupture zone, which ruptures under a correspondingly high internal gas pressure and allows gas to escape in this region. The battery cells are spaced apart from the venting element to varying degrees, so that the high-temperature gas flow of the battery cells can heat up a plurality of other battery cells to a large extent in the process of flowing to the degassing element. Summary of the invention

[0003] Against this background, it is an object of the present invention to provide a motor vehicle traction battery with improved hot gas dissipation.

[0004] According to the invention, this object is achieved by a motor vehicle having a traction battery module having the features described below.

[0005] The motor vehicle according to the invention has a traction battery module having a tightly sealed module housing in which at least one cell stack pair is arranged. The module housing is sealed in a substantially gastight manner. The cell stack pair (in relation to the longitudinal axis of the vehicle) consists of a left cell stack and a right cell stack. Each cell stack consists of at least two battery cells. The traction battery module is arranged on the vehicle floor and extends symmetrically in the vehicle transverse direction relative to the middle of the vehicle. The module housing has a bottom wall located in a horizontal plane. Inside the module housing and approximately in the middle of the vehicle, a free gas space is formed between the left cell stack and the right cell stack, which gas space is not filled with any filling material, in particular without a heat-conducting substance. The module bottom wall has an exhaust element in the region of the gas space and approximately in the middle of the vehicle, through which the hot gases from the battery cells can escape from the vehicle floor downwards in the middle of the vehicle to the outside of the vehicle if necessary. The traction battery module is therefore designed such that each cell stack is directly connected to the gas element in a fluid-connected manner, so that the hot gases escaping from each cell stack can flow directly to the exhaust element via the gas space without having to flow significantly through other cell stacks. This makes it possible to reliably avoid chain reactions within the traction battery module. Since the exhaust is carried out directly from the middle of the vehicle to the underside of the vehicle via the exhaust element, a short flow path from each cell stack to the exhaust element is achieved and local limited heating of the traction battery module is ensured. In addition, good occupant protection is ensured by the hot gases escaping directly to the middle of the underside of the vehicle.

[0006] Preferably, the gas space is substantially square and has a width of at least 10 cm in the transverse direction of the vehicle. Preferably, the gas space has a width of at most 30 cm in the transverse direction of the vehicle. Preferably, the gas space extends vertically over the entire vertical extension of adjacent cell stacks or in the longitudinal direction over the entire longitudinal extension of adjacent cell stacks. Thus, each cell stack adjoins the gas space with the cell stack side almost over the entire surface. In this way, it is ensured that the flow resistance between each cell stack and the gas space approaches zero accordingly and that an overpressure can be formed in the gas space as quickly as possible, thereby opening the exhaust element.

[0007] Preferably, the venting element is designed as a gas-tight rupture disk. The rupture disk is designed such that it ruptures reliably at a significant overpressure, so that in the event of a thermal fault, the venting element is reliably opened in this way. The rupture disk can be realized, for example, simply as a material weakening of the bottom wall of the module housing, but the rupture disk can also be designed as a mechanical overpressure valve, which closes again after the internal overpressure has been reduced.

[0008] Preferably, the motor vehicle has a planar and liquid-cooled cooling floor below the module bottom wall, by means of which the bottom side of the traction battery module is actively cooled. The cooling floor has an exhaust opening in the middle of the vehicle in an orientation (relative to the vehicle transverse direction) vertically aligned with the exhaust element. The exhaust opening is thus vertically aligned with the exhaust element. In this way, the cooling floor does not prevent the exhaust of the traction battery module in the event of a fault.

[0009] Preferably, two cell stack pairs can be provided inside the module housing, which are arranged adjacent to one another when viewed in the longitudinal direction of the vehicle. In principle, a single exhaust element can be assigned to the two gas spaces in the middle. However, it is particularly preferred that the two cell stack pairs and the two gas spaces respectively assigned to the two cell stack pairs are isolated from one another in a gas-tight manner, wherein each gas space is respectively assigned a respective exhaust element.

[0010] Preferably, the four side walls of the module housing are formed integrally from an extruded profile.

[0011] In general, the present invention discloses the following technical solution 1, and the following 2-9 are preferred technical solutions of the present invention:

[0012] 1. A motor vehicle (100) having a traction battery module (10), the traction battery module having a tightly sealed module housing (20), in which at least one cell stack pair (600) is accommodated, the at least one cell stack pair consisting of a left cell stack and a right cell stack (60, 60') each consisting of at least two battery cells (62),

[0013] The traction battery module (10) is arranged on a vehicle floor (102), extends symmetrically with respect to a vehicle center (M) in a vehicle transverse direction (X), and has a bottom wall (26) on a horizontal plane,

[0014] A gas space (66) is formed in a module housing (20) located in the middle (M) of the vehicle and between the left unit stack (60) and the right unit stack (66') relative to the transverse direction (X) of the vehicle, wherein the module bottom wall (26) has an exhaust element (30) in the region of the gas space (66) in the middle of the vehicle.

[0015] 2. A motor vehicle (100) having a traction battery module (10) according to 1 above, wherein the gas space (66) is substantially square and has a width (B) of at least 10 cm in the vehicle transverse direction (X).

[0016] 3. A motor vehicle (100) having a traction battery module (10) according to any one of the above 1-2, wherein the gas space (66) is substantially square and has a width (B) of at most 30 cm in the vehicle transverse direction (X).

[0017] 4. A motor vehicle (100) having a traction battery module (10) according to any one of the above 1-3, wherein the gas space (66) is substantially square and extends in the vertical direction (Z) over the entire vertical extension of the cell stack (60, 60').

[0018] 5. A motor vehicle (100) having a traction battery module (10) according to any one of the above 1-4, wherein the gas space (66) is substantially square and extends over the entire longitudinal extension (L) of the cell stack (60, 60') in the longitudinal direction (Y) of the vehicle.

[0019] 6. A motor vehicle (100) having a traction battery module (10) according to any one of the above 1 to 5, wherein the venting element (30) is designed as a gas-tight rupture disk (32).

[0020] 7. A motor vehicle (100) having a traction battery module (10) according to any of the above 1 to 6, wherein a flat and liquid-cooled cooling base plate (40) is arranged below the bottom wall (26) of the module, and the cooling base plate has an exhaust opening (46) located in the middle of the vehicle in an orientation vertically aligned with the exhaust element (30).

[0021] 8. A motor vehicle (100) having a traction battery module (10) according to any of the above 1 to 7, wherein at least two cell stack pairs (600, 600') are provided, and when viewed in the longitudinal direction (Y) of the vehicle, the at least two cell stack pairs are arranged adjacent to each other, wherein two gas spaces (66, 66') are isolated from each other in a gas-tight manner and each gas space (66, 66') is correspondingly assigned a respective exhaust element (30, 30').

[0022] 9. A motor vehicle (100) having a traction battery module (10) according to any one of the preceding items 1 to 8, wherein the four side walls (21-24) of the module housing (20) are formed integrally from an extruded profile. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following is a detailed explanation of the embodiments of the present invention with reference to the accompanying drawings. In the accompanying drawings:

[0024] Figure 1 schematically shows a motor vehicle with a traction battery module located on the vehicle floor,

[0025] Figure 2 Shown in cross section Figure 1 The traction battery module

[0026] Figure 3 Shown in horizontal section Figure 1 and Figure 2 traction battery modules, and

[0027] Figure 4 by Figures 1 to 3 A bottom view of the vehicle floor is shown with the cooling floor beneath the traction battery module. DETAILED DESCRIPTION

[0028] exist Figure 1 Schematically shown in FIG. 1 is a motor vehicle 100 with a traction motor 104, which has a plurality of traction battery modules 10 on a vehicle floor 102, which together form a traction battery of the motor vehicle 100. The driving direction of the motor vehicle 100 is the vehicle longitudinal direction Y, the transverse direction is the vehicle transverse direction X and its vertical line is the vehicle vertical axis Z.

[0029] Each traction battery module 10 has two cell stack pairs 600, 600', which are respectively composed of a left cell stack 60 and a right cell stack 60', wherein the left cell stack 60 is located in the left half of the vehicle to the left of the vehicle center M and the right cell stack 60' is located in the right half of the vehicle to the right of the vehicle center M. The traction battery module 10 generally extends over a large part of the width of the vehicle floor 102. Each cell stack 60, 60' is respectively composed of a plurality of battery cells 62, which are located in a vertical transverse plane in the present case so that the near side narrow side of each battery cell 62 adjoins a square gas space 66 in the middle of the module, which is a free space not filled with solid matter. The gas space 66 extends in the longitudinal direction over the entire longitudinal extension and in the vertical direction over the entire vertical extension of the two adjacent cell stacks 60, 60'. The square gas space 66 has a width B of 20 cm in the vehicle transverse direction X, for example.

[0030] The square and hermetically sealed metal module housing 20 has a left side wall 21, a right side wall 22, a top wall 25, a bottom wall 26, a front end wall 23 and a rear end wall 24. The module housing 20 is partially formed by an extruded profile body, which forms four long housing walls 21, 22, 25, 26 and a partition wall 80, while the relatively small-area left and right side walls 21 and 22 are already assembled to the extruded profile body in a hermetically sealed manner (e.g., by welding) after the two unit stack pairs 600, 600' have been inserted into the profile body.

[0031] In the region of the vehicle center M and approximately in the middle of the respective gas space 66, 66' on the bottom wall 26 with respect to the transverse direction x, a venting element 30 is arranged, which is in principle gas-tight, but is designed such that it is permanently damaged if a defined pressure difference between the gas space 66, 66' and the atmospheric pressure on the outside is exceeded. The venting element 30 is formed by a rupture disk 32, which is located gas-tight in the venting opening 28 of the bottom wall 26.

[0032] A liquid-cooled cooling base 40 is arranged below the bottom wall 26 of the module housing 20, which is actively cooled substantially over the entire surface by means of a cooling liquid 44 flowing through cooling channels 42. The cooling base 40 is thermally coupled to the module housing bottom wall 26 over the entire surface, so that a large part of the heat generated by the traction battery module 10 during charging operation or traction operation is discharged via the cooling base 40. The cooling base 40 has corresponding exhaust openings 46 in an orientation vertically aligned with the exhaust element 30, through which exhaust openings the gas can escape from the gas space 66 vertically downward relative to the center of the vehicle in the case of exhaust.

[0033] exist Figure 3 As can be seen in the horizontal section, the external module housing 20 comprises two cell stack pairs 60, 60', which are isolated from each other in an airtight manner by a partition wall 80 located in a vertical transverse plane, so that each cell stack pair 600, 600' is assigned a respective gas space 66, 66' and a respective exhaust element 30, 30.

Claims

1. A motor vehicle (100) having a traction battery module (10), the traction battery module having a tightly sealed module housing (20), in which at least two cell stack pairs are arranged, viewed in the longitudinal direction (Y) of the vehicle, the at least two cell stack pairs being arranged adjacent to each other, each cell stack pair consisting of a left cell stack (60) and a right cell stack (60'), the left cell stack (60) and the right cell stack (60') each consisting of at least two battery cells (62), The traction battery module (10) is arranged on a vehicle floor (102), extends symmetrically with respect to a vehicle center (M) in a vehicle transverse direction (X), and has a bottom wall (26) on a horizontal plane, wherein at least two gas spaces are formed between the left cell stack (60) and the right cell stack (60') in a module housing (20) located in the middle (M) of the vehicle and relative to the transverse direction (X) of the vehicle, wherein the two gas spaces are isolated from each other in a gas-tight manner and each gas space is correspondingly assigned a respective exhaust element, wherein the exhaust element is arranged on the bottom wall (26), A flat, liquid-cooled cooling base plate (40) is arranged below the bottom wall (26), which has an exhaust opening (46) in the middle of the vehicle in a direction vertically aligned with the exhaust element.

2. The motor vehicle (100) having a traction battery module (10) according to claim 1, wherein the gas space is cuboid and has a width (B) of at least 10 cm in the vehicle transverse direction (X).

3. A motor vehicle (100) with a traction battery module (10) according to claim 1 or 2, wherein the gas space is cuboid and has a width (B) of at most 30 cm in the vehicle transverse direction (X).

4. A motor vehicle (100) with a traction battery module (10) according to claim 1 or 2, wherein the gas space is square and extends in the vertical direction (Z) over the entire vertical extension of the cell stack.

5. A motor vehicle (100) with a traction battery module (10) according to claim 1 or 2, wherein the gas space is cuboid and extends in the vehicle longitudinal direction (Y) over the entire longitudinal extension (L) of the cell stack.

6. The motor vehicle (100) having a traction battery module (10) according to claim 1 or 2, wherein the venting element is designed as a gas-tight rupture disk (32).

7. A motor vehicle (100) having a traction battery module (10) according to claim 1 or 2, wherein the four side walls of the module housing (20) are formed integrally from an extruded profile.

Images