DEGASSING DEVICE, BATTERY, AND MOTOR VEHICLE

Abstract

A degassing device for discharging gases from a battery for a motor vehicle, which battery includes at least one first battery cell with an at least releasable first degassing opening. The degassing device has at least one first gas space which can be fluidically coupled to the releasable first degassing opening of the at least one first battery cell, so that gas exiting the degassing opening can be introduced into the at least one first gas space, and has a particle trap device for separating particles from the gas flowing through the particle trap device. The particle trap device is fluidically connected to the at least one first gas space.

Claims

1. A degassing device for discharging gases from a battery of a motor vehicle, comprising: at least one first gas space which can be fluidically coupled to a releasable first degassing opening of at least one first battery cell, so that gas exiting the first degassing opening can be introduced into the at least one first gas space, and a particle trap device for separating particles from the gas flowing through the particle trap device, wherein the particle trap device is fluidically connected to the at least one first gas space, wherein the degassing device provides a first flow path from the at least one first gas space into the particle trap device, the cross-section of which is larger within at least one area of the particle trap device than in the at least one first gas space.

2. The degassing device according to claim 1, wherein the at least one first gas space is designed as a first degassing channel, which has a length (L) in a longitudinal direction of extension (x) of the first degassing channel that is greater than a width (B) and a height of the first degassing channel, wherein the first flow path extends along the longitudinal direction of extension (x) of the first degassing channel.

3. The degassing device according to claim 1, wherein the particle trap device is designed to cool a gas flow passing through the particle trap device as it passes through.

4. The degassing device according to claim 1, wherein the particle trap device has at least one inlet area and one outlet area, wherein the particle trap device is designed in such a way that the first flow path is deflected several times from at least one inlet area to the outlet area.

5. The degassing device according to claim 1, wherein the particle trap device has a particle filter arranged in the first flow path, in particular made of steel wool.

6. The degassing device according to claim 1, further comprising at least one second degassing channel, spatially separated from the first, which is fluidically coupled to the particle trap device and which can be fluidically coupled to a releasable second degassing opening of at least one second battery cell of the battery, so that the gas exiting the second degassing opening can be introduced into the at least one second degassing channel and guided into the particle trap device along a second flow path.

7. A battery for a motor vehicle, comprising: a degassing device having at least one first gas space which can be fluidically coupled to a releasable first degassing opening of at least one first battery cell, so that gas exiting the first degassing opening can be introduced into the at least one first gas space, and a particle trap device for separating particles from the gas flowing through the particle trap device, wherein the particle trap device is fluidically connected to the at least one first gas space, wherein the degassing device provides a first flow path from the at least one first gas space into the particle trap device, the cross-section of which is larger within at least one area of the particle trap device than in the at least one first gas space.

8. The battery according to claim 7, further comprising a first battery area with at least one first row of cells with several first battery cells arranged next to one another in a first direction (x), which battery cells each have releasable first degassing openings, and a second battery area with at least one second row of cells with several second battery cells arranged next to one another in the first direction, which battery cells each have releasable second degassing openings, wherein the particle trap device is arranged between the first battery area and the second battery area with respect to the first direction (x), wherein the first degassing channel is coupled to the releasable first degassing openings of the first battery cells and extends in the first direction (x) with respect to the particle trap device, and the second degassing channel is coupled to the releasable second degassing openings of the second battery cells and extends opposite the first direction (x) with respect to the particle trap device.

9. The battery according to claim 8, further comprising a cooling base on which the at least one first battery cell is arranged, and the degassing device has an exhaust gas channel which is coupled to the outlet opening of the particle trap device, wherein the exhaust gas channel is arranged on a side of the cooling base facing away from the at least one battery cell, in particular wherein the exhaust gas channel is provided by a spatial region between the cooling base and the underbody protection.

10. A motor vehicle comprising: a battery with a degassing device having at least one first gas space which can be fluidically coupled to a releasable first degassing opening of at least one first battery cell, so that gas exiting the first degassing opening can be introduced into the at least one first gas space, and a particle trap device for separating particles from the gas flowing through the particle trap device, wherein the particle trap device is fluidically connected to the at least one first gas space, wherein the degassing device provides a first flow path from the at least one first gas space into the particle trap device, the cross-section of which is larger within at least one area of the particle trap device than in the at least one first gas space.

11. The degassing device according to claim 2, wherein the particle trap device is designed to cool a gas flow passing through the particle trap device as it passes through.

12. The degassing device according to claim 2, wherein the particle trap device has at least one inlet area and one outlet area, wherein the particle trap device is designed in such a way that the first flow path is deflected several times from at least one inlet area to the outlet area.

13. The degassing device according to claim 3, wherein the particle trap device has at least one inlet area and one outlet area, wherein the particle trap device is designed in such a way that the first flow path is deflected several times from at least one inlet area to the outlet area.

14. The degassing device according to claim 2, wherein the particle trap device has a particle filter arranged in the first flow path, in particular made of steel wool.

15. The degassing device according to claim 3, wherein the particle trap device has a particle filter arranged in the first flow path, in particular made of steel wool.

16. The degassing device according to claim 4, wherein the particle trap device has a particle filter arranged in the first flow path, in particular made of steel wool.

17. The degassing device according to claim 2, further comprising at least one second degassing channel, spatially separated from the first, which is fluidically coupled to the particle trap device and which can be fluidically coupled to a releasable second degassing opening of at least one second battery cell of the battery, so that the gas exiting the second degassing opening can be introduced into the at least one second degassing channel and guided into the particle trap device along a second flow path.

18. The degassing device according to claim 3, further comprising at least one second degassing channel, spatially separated from the first, which is fluidically coupled to the particle trap device and which can be fluidically coupled to a releasable second degassing opening of at least one second battery cell of the battery, so that the gas exiting the second degassing opening can be introduced into the at least one second degassing channel and guided into the particle trap device along a second flow path.

19. The degassing device according to claim 4, further comprising at least one second degassing channel, spatially separated from the first, which is fluidically coupled to the particle trap device and which can be fluidically coupled to a releasable second degassing opening of at least one second battery cell of the battery, so that the gas exiting the second degassing opening can be introduced into the at least one second degassing channel and guided into the particle trap device along a second flow path.

20. The degassing device according to claim 5, further comprising at least one second degassing channel, spatially separated from the first, which is fluidically coupled to the particle trap device and which can be fluidically coupled to a releasable second degassing opening of at least one second battery cell of the battery, so that the gas exiting the second degassing opening can be introduced into the at least one second degassing channel and guided into the particle trap device along a second flow path.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0028] Exemplary embodiments of the invention are described hereinafter. The figures show the following:

[0029] FIG. 1 a schematic cross-sectional representation of a battery with a degassing device according to an exemplary embodiment of the invention; and

[0030] FIG. 2 a schematic plan view of a battery with a degassing device according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION

[0031] The exemplary embodiments explained hereinafter are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention to be considered independently of one another, which each also refine the invention independently of one another. Therefore, the disclosure is also intended to comprise combinations of the features of the embodiments other than those illustrated. Furthermore, the described embodiments can also be supplemented by further, above-described features of the invention.

[0032] In the figures, the same reference numerals designate elements that have the same function.

[0033] FIG. 1 shows a schematic cross-sectional representation of a battery 10, in particular a high-voltage battery 10, for a motor vehicle with a degassing device 12 according to an exemplary embodiment of the invention. In this example, the battery 10 has several battery modules 14 each with several battery cells 16. For reasons of clarity, only a few of the battery cells 16 in this case are provided with a reference numeral. Four battery modules 14 are shown here as an example. The battery 10 can generally also comprise more or fewer battery modules, and in particular also more or fewer battery cells 16.

[0034] FIG. 2 shows the associated plan view of the battery 10, in particular without the housing cover, some of the battery modules 14 and the battery cells 16 thereof being provided with a reference numeral here as an example for reasons of clarity.

[0035] If a battery cell 16 is experiencing thermal runaway, gases are produced inside such a battery cell 16, which gases must be discharged in a controlled manner in order to prevent these battery cells 16 from exploding. For this purpose, the respective battery cells 16 have a releasable degassing opening 18, which can be designed as a bursting membrane, for example. In FIG. 1, these releasable degassing openings 18 are indicated by dashed lines on the upper side of the respective battery cells 16, with only some of these degassing openings 18 being provided with a reference numeral in turn for reasons of clarity. The gases 20 exiting the battery cells 16 are also illustrated by arrows. Gases 20 exiting a battery cell 16 are initially extremely hot and comprise material particles, such as dust, which, if the materials were to accumulate at bottlenecks in or outside the battery system in an uncontrolled manner, could lead, for example, to a blockage of flow cross-sections and/or short-circuiting of other cells 16 within the battery 10. In order to prevent this, the battery 10 advantageously has a degassing device 12. This comprises, on the one hand, degassing channels 22. In general, the degassing device 12 has at least one such degassing channel 22 which can be fluidically coupled to the degassing openings 18 of the battery cells 16, so that the gas flow 20 exiting the degassing openings 18 can be routed or introduced into such a degassing channel 22. This can be accomplished in a simple manner by the degassing channel 22 being arranged above the battery cells 16 in relation to the z-direction shown and having corresponding channel openings 24 which are arranged to overlap with the respective degassing openings 18 of the battery cell 16. Furthermore, this degassing channel 22 is designed to be as narrow as possible, so that the width B (see FIG. 2) thereof is preferably smaller than a module width b and also smaller than a length L of such a degassing channel 22. In particular, the length L of such a degassing channel 22 should represent the greatest dimension of such a degassing channel. Furthermore, the degassing device 12 comprises a particle trap device 26 which is designed to separate particles from the gas 20 flowing through the particle trap device 26. Such separated particles 28 are shown as an example in FIG. 1. This particle trap device 26 is also fluidly connected to the respective degassing channels 22. A flow path 30 is thus provided, which defines the path followed by the gas 20 flowing out of the battery cells 16, so that this flow path 30 can also be considered illustrated by the arrows shown in FIG. 1 in the same manner. This flow path 30 thus extends from the cells 16, through the degassing channels 22, to the particle trap device 26, and through this to a final outlet opening 32.

[0036] The flow path 30 is advantageously designed in such a way that the flow cross-section increases at the transition from the degassing channels 22 to the particle trap device 26, in particular by a multiple, for example by a factor of 20. For example, the cross-section of a degassing channel, i.e. a section parallel to the yz-plane in this example, can be 4 cm.sup.2 and the cross-sectional area of the particle trap device 26 in the same cross-sectional plane, i.e. again parallel to the yz-plane, can be 80 cm.sup.2. Due to the fact that the particle trap device 26 is elongated in the y-direction, as can be seen above all in FIG. 2, such a large cross-sectional area of the particle trap device 26 can be provided in an especially simple manner. A cross-sectional enlargement from the degassing channel 22 to the particle trap device 26 can be used by all the degassing channels 22 in the same manner. Such a cross-sectional enlargement has the great advantage that the gas 20 can be cooled again as a result, which promotes particle separation. In addition, the fact that the degassing channels 22 themselves are designed with a relatively small cross-section in the direction of flow 30 ensures that the gas 20 does not expand particularly strongly when it exits the battery cells 16 and thus does not cool down significantly in the degassing channels 22 themselves, which means that uncontrolled depositing of particles 28 within the degassing channels 22 can be avoided or at least reduced before the particle trap device 26 is reached. This means that the particles 28 are only separated where there is sufficient space for this, namely in the particle trap device 26.

[0037] Furthermore, the particle trap device 26 is designed with a labyrinth system 34 in this example. Such a labyrinth system 34 causes several deflections of the flow path 30 from an inlet opening 36, particularly the several inlet openings 36 assigned to the respective degassing channels 22, to the outlet opening 38 of the particle trap device 26. This labyrinth structure or this labyrinth system 34 can also have dead ends 40, which can likewise be used for increased particle separation. Such a mechanical deflection and labyrinth structure also promotes particle separation in addition to the widening of the cross-section. The particle trap device 26 can also have other or additional devices for particle separation, for example a filter-like wadding made of steel wool. Sparks above all can hereby be efficiently filtered out.

[0038] The gas finally exiting the outlet opening 38 of the particle trap device 26 has therefore cooled down considerably and now contains only a few particles, which, however, are largely harmless in terms of possible ignition of the exiting gas due to the low speed and low temperature thereof. Furthermore, an exhaust gas channel 42 is coupled to the outlet opening 38 of the particle trap device 26, via which exhaust gas channel the exiting gas 20 can be discharged from the battery 10 and from the motor vehicle as far as the final outlet opening 32. As a result, the gas 20 has to cover a longer distance before it exits the opening 32, which leads to an additional slowing down and cooling of the gas 20.

[0039] It is also especially advantageous if this exhaust gas channel 42 is provided by an existing structure of the battery 10 and/or of the motor vehicle. In this example, the exhaust gas channel 42 is provided by an intermediate space that is located between a cooling base 44 of the battery 10 for cooling the battery cells 16 and the underbody protection 46 of the motor vehicle. The cooling base 44 can also have cooling channels 48 through which a coolant can flow. In addition, this intermediate space providing the exhaust gas channel 42 can extend over the entire x-y-plane of the battery 10.

[0040] Overall, the examples show how the invention can provide a particle trap in a high-voltage battery, which particle trap makes it possible to discharge a gas exiting the battery cells in an especially simple and safe manner in the event of thermal propagation.