Power battery device for vehicle and motor vehicle having power battery device

Abstract

The present invention relates to a motor vehicle (10) and a power battery device (12), the power battery device having at least one battery module (16) and a battery housing (20), the at least one battery module having at least one battery cell (18), the at least one battery module (16) being arranged in the battery housing, wherein the at least one battery cell (18) has a diffusion opening (26) for discharging diffusion gas from the battery cell (18), wherein at least one protective element (28) is provided in a battery housing wall of the battery housing (20), the at least one protective element being constructed to destabilize under the action of diffusion gas and to provide an opening through the battery housing wall for discharging diffusion gas from the power battery device (12).

Description

Technical Field

[0001] The present invention relates to a power battery device for a vehicle, the power battery device having at least one battery module and a battery housing, the battery module having at least one battery cell, the battery module being arranged in the battery housing, wherein the at least one battery cell has a diffusion opening for discharging diffusion gas from the battery cell. In addition, the present invention also relates to a motor vehicle having such a power battery device. Background Art

[0002] Current power batteries or high-voltage battery storage systems for electric vehicles (BEV) must meet high sealing requirements with respect to environmental influences such as humidity, salt load and mechanical influences. In addition, the power battery equipment for the power battery must be designed in such a way that the vehicle occupants are protected in the event of diffusion of the battery cells. Battery diffusion, also known as thermal runaway (Thermal Propagation, Thermal Runaway), is an exothermic chemical reaction in the battery cells, which can produce high-pressure hot diffusion gases, which can cause damage to the power battery and the vehicle. Such diffusion situations can be caused, for example, by an internal short circuit in the battery cell. Although these diffusion situations are rare, complex measures are still used to increase safety, such as providing, for example, steel inserts or additional fire protection measures on the battery cover.

[0003] A battery of this type for use in a vehicle is known from DE 10 2008 034 879 A1, wherein the battery is arranged in a battery housing having an opening for reducing the internal pressure, wherein a pipe connection for exhaust gas discharge is arranged at the opening.

[0004] A safety element for a battery cell is known from document DE 10 2017 219 553 A1, wherein the safety element comprises a liquid receiving portion having an inner space filled with a liquid, wherein the liquid receiving portion and the receiving element are in particular formed integrally, and wherein the safety element further comprises at least one predetermined breaking point, which is designed to break when the liquid undergoes an at least partial phase change into a gaseous state.

[0005] Document DE 10 2014 201 165 A1 discloses a battery module having a plurality of electrically connected battery cells, wherein the individual battery cells are temperature-controlled by a temperature-control fluid. A channel system extends between the battery cells, through which the temperature-control fluid flows. The channel system is completely separated from the exhaust system of the battery cells.

[0006] A disadvantage of existing fire protection concepts for power batteries is that they are complex and require a large amount of installation space, which limits the size of the battery. Summary of the invention

[0007] The object of the present invention is to provide a cost-effective protection for a battery module.

[0008] This object is achieved by the independent claim. Advantageous developments of the invention are disclosed in the dependent claims, the following description and the drawings.

[0009] The present invention provides a power battery device for a vehicle, the power battery device having at least one battery module and a battery housing, the battery module having at least one battery cell, the battery module being arranged in the battery housing, wherein the at least one battery cell has a diffusion opening for discharging diffusion gas (Propagations gas) from the battery cell. The diffusion opening is usually arranged at the single pole of the battery cell. According to the present invention, the power battery device provides at least one protective element in the battery housing wall of the battery housing, the protective element being configured to destabilize under the action of the diffusion gas and provide an opening through the battery housing wall for discharging the diffusion gas from the power battery device.

[0010] In other words, the battery housing of the power battery device is sealed and protected from external influences in a normal state. If a diffusion situation occurs, that is, the diffusion gas escapes from the diffusion opening of the battery cell, at least one protective element is provided in the battery housing wall, which breaks and / or melts due to the effect of the diffusion gas. As a result, the protective element can release an opening through the battery housing wall, wherein the diffusion gas can flow out from the power battery device from the opening. The protective element can be constructed as a predetermined fracture site and / or weak site in the battery housing wall, wherein the protective element can release the opening, for example, due to the pressure of the diffusion gas and / or the temperature of the diffusion gas. In particular, the protective element can soften due to the temperature of the diffusion gas and be squeezed out by the pressure of the diffusion gas. The protective element can be constructed above the opening of the battery housing, for example, by a plastic layer and / or a metal layer. The protective element can in particular have a predetermined fracture strength and / or a predetermined melting point, and these characteristics are preferably predetermined by the gas pressure of the diffusion gas or the temperature of the diffusion gas.

[0011] Preferably, the protective element can have a different material composition than the battery housing, wherein the battery housing can be composed, for example, of plastic, metal, in particular steel and / or aluminum, composite materials and / or material composites. For example, the battery housing can have a metal that is injection-molded with plastic. Preferably, a plurality of battery cells can be provided with respective diffusion openings, wherein a respective protective element can be provided in the battery housing wall for each diffusion opening.

[0012] The advantage obtained by the present invention is that a cost-effective method can be realized to discharge diffusion gas from the power battery device and thus improve the safety of the power battery device and / or the vehicle. In particular, expensive components such as pressure relief valves can be omitted and installation space can be saved, thereby, for example, larger battery modules can be provided.

[0013] The invention also includes embodiments that produce other advantages.

[0014] One embodiment proposes that the corresponding protection element is arranged opposite to the diffusion opening of the corresponding battery cell. In other words, each protection element and each diffusion opening are respectively arranged in pairs, and each protection element and each diffusion opening are arranged opposite to each other. That is to say, the diffusion opening of each battery cell is directly aligned with the battery housing wall with the corresponding protection element, so that the diffusion gas directly reaches the protection element after escaping from the battery cell. The advantage obtained by this embodiment is that the protection element can be destabilized in advance under diffusion conditions, thereby quickly achieving the opening through the battery housing wall and thus avoiding overpressure and / or high heat generation in the power battery device.

[0015] Preferably, it is provided that the diffusion opening and the corresponding protective element are arranged toward the underside of the power battery device, wherein the underside of the power battery device in the specified installation position particularly points toward the underside of the vehicle. In other words, the battery cells, in particular the cell poles arranged with the diffusion openings, can be oriented downwards in the direction of the ground. As a result, the diffusion gas can be released in the direction of the ground, thereby in particular protecting vehicle occupants in the opposite direction.

[0016] Another embodiment provides that the corresponding protective element is designed as a material weakness of the battery housing wall, wherein the material weakness is designed to melt due to the temperature of the diffusion gas. The material weakness can be realized, for example, by a material constriction in the battery housing wall and / or a material that is less pressure-resistant and / or less heat-resistant than the battery housing wall can be used. This embodiment has the advantage that a cost-effective protective element can be provided by means of a material weakness.

[0017] Preferably, it is provided that the material weakness has a material with a predetermined melting point and / or a predetermined material thickness. The melting point of the material can be predetermined, for example, by the expected heat of the diffusion gas, and the material thickness can be predetermined by a compromise between the protection against external influences and the time required for the diffusion gas to melt the material thickness.

[0018] It is particularly preferred that the corresponding protective element is mainly composed of plastic. In particular, the plastic in a solid state can provide reliable mechanical protection to the outside, and at the same time, the plastic can melt quickly under the action of heat, especially under the action of heat from the diffusion gas, so that an opening through the battery housing can be provided. Preferably, the plastic is a thermoplastic, such as polyethylene, polypropylene, polystyrene, polyester, polyoxymethylene, polyamide, polyethylene terephthalate (PET) and other partially crystalline or amorphous thermoplastics. The advantage obtained by the design scheme of forming the protective element from plastic is that a low-cost protective element can be provided.

[0019] In particular, it is proposed that the battery housing wall has a metal which is designed to maintain the stability of the battery housing and protect the battery module from mechanical damage, wherein the metal has at least one notch for at least one protective element made of plastic. In other words, a notch is provided in the metal of the battery housing wall for each protective element, wherein the notch is closed by a protective element made of plastic. In particular, it can be proposed that the battery housing has a metal which is injection-molded with plastic, which can be manufactured particularly advantageously during production. This has the advantage that mechanical protection and protection against diffusion gases can be provided for the battery module.

[0020] Another embodiment proposes that the battery housing has a cooling channel on the side facing the battery module, and the cooling channel is particularly designed to be meandering, wherein the protective element is arranged in the gap of the cooling channel. In other words, the protective element is arranged in the gap between the cooling channels. The advantage obtained by this is that the battery module can be cooled by the cooling channel and despite this, there is still a space for the protective element between the cooling channels, and the diffusion gas can escape through the space after the protective element is unstable. In addition, the cooling channel can also be used to further ensure the stability of the battery housing. In addition, the cooling channel can cool the corresponding protective element in the normal state of the power battery device, so that the protective element will not be unstable in normal operation, especially for example due to high external temperature and melt. In particular, the temperature of the diffusion gas in the diffusion state can be many times higher than the temperature in the normal state, thereby exceeding the cooling effect of the cooling element on the protective element. Through this embodiment, the mechanical protection of the battery housing wall can be better maintained and the discharge of the diffusion gas can be provided in the diffusion state.

[0021] Another embodiment provides that the battery module is sealed to the outside by means of a potting material. In particular, the battery module can be sealed by the potting material in the direction of the opening for inserting the battery module into the battery housing. The potting material can protect and seal the battery module from external moisture and / or other environmental influences. The advantage resulting from this embodiment is that the diffusion gas can only escape via the opening of the protective element provided for escape and thus other vehicle components, in particular vehicle occupants, can be protected from the diffusion gas.

[0022] Another aspect of the invention relates to a motor vehicle having a power battery device according to one of the above-described embodiments. The motor vehicle according to the invention provides the same advantages and variant possibilities as in the power battery device. The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular a passenger car or a truck, or as a passenger bus or a motorcycle.

[0023] The present invention also includes improvements of the motor vehicle according to the present invention, which have the features already described in conjunction with the improvements of the power battery device according to the present invention. For this reason, the corresponding improvements of the motor vehicle according to the present invention will not be described here.

[0024] The present invention also includes combinations of features of the described embodiments. Therefore, the present invention also includes implementations which respectively have a combination of features of a plurality of the described embodiments, as long as these embodiments are not described as mutually exclusive. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Embodiments of the present invention are described below. To this end, it is shown that:

[0026] Figure 1 A motor vehicle having a power battery device according to an exemplary embodiment is schematically shown;

[0027] Figure 2 A motor vehicle having a power battery arrangement according to a further exemplary embodiment is schematically shown. DETAILED DESCRIPTION

[0028] The embodiment set forth below is a preferred embodiment of the present invention. In the embodiment, the various parts described in the embodiment are respectively the features of the present invention that can be considered independently of each other, and these features also improve the present invention independently of each other. Therefore, the present disclosure is intended to include the combination of the features of the embodiment except the combination shown. In addition, the embodiment can also be supplemented by other features in the features already described of the present invention.

[0029] In the figures, the same reference numerals respectively denote elements with the same function.

[0030] Figure 1 A highly schematic motor vehicle 10 is shown with a power battery device 12 according to an exemplary embodiment, wherein the power battery device 12 can be mounted to the underside of the motor vehicle 10, for example, by fasteners 14. In particular, the power battery device 12 includes a battery module 16 having a plurality of battery cells 18. The battery module 16 can be arranged in a battery housing 20, wherein the battery module 16 can be sealed upwardly by a potting material 22 and a module cover 24.

[0031] Preferably, the battery cells 18 are arranged with diffusion openings 26, which can be arranged in particular at the cell poles, in the direction of the underside of the power battery device 12, that is, in the direction of the underside of the motor vehicle 10. In particular, in the case of diffusion, the diffusion gas can escape through the diffusion opening 26 of the respective battery cell 18. The battery housing wall of the battery housing 20 that is opposite the respective diffusion opening 26 can have a corresponding protective element 28, wherein the respective protective element 28 is designed to destabilize under the action of the diffusion gas and to provide an opening through the battery housing wall of the battery housing 20 of the power battery device 12. In particular, the protective element 28 can provide an opening to the underside of the motor vehicle 10, for example to the road, through which the diffusion gas can escape.

[0032] Preferably, the corresponding protective element 28 can be made mainly of plastic, in particular thermoplastic, which changes from a solid state to a liquid state at a predetermined melting point. In other words, the protective element 28 can be melted under the action of the diffusion gas. Alternatively or additionally, the protective element 28 can be configured as a material weakness of the battery housing wall. That is, for the protective element 28, the material thickness of the battery housing wall can be smaller than the material thickness in other areas.

[0033] It can be particularly preferably proposed that the battery housing 20 has a metal-plastic hybrid structure. That is, the metal 30, in particular steel or aluminum, can be injection-molded with plastic. This can improve the mechanical protection of the battery module 16 by the battery housing 20, wherein the metal of the metal-plastic hybrid component preferably has a gap at the location of the corresponding protection element 28. These gaps are preferably closed by the injection-molded plastic layer, wherein the gap and the plastic layer together form the protection element 28. That is, the injection-molded metal 30 in the battery housing can be interrupted at the location of the protection element 28 so that an outward opening can be provided after the protection element is melted through in the case of diffusion. The design scheme as a metal-plastic hybrid component has the following advantages, namely, the battery housing 20 can be manufactured integrally with the protection element 28, thereby saving manufacturing time and costs when manufacturing the power battery device 12.

[0034] Figure 2Another exemplary embodiment of the power battery device 12 of the motor vehicle 10 is shown. In this embodiment, as shown in FIG. Figure 1 As in the figure, the battery cells 18 of the battery module 16 are oriented downward with respective diffusion openings 26, wherein in this figure also corresponding protective elements 28 in the battery housing wall of the battery housing 20 are arranged opposite the corresponding diffusion openings 26. For reasons of clarity, some reference numerals have been omitted in this figure.

[0035] exist Figure 2 In the embodiment shown in , the battery housing 20, in particular the bottom of the battery housing 20, additionally has a cooling channel 32, which extends, for example, in a meandering manner on the bottom of the battery housing 20. In order to transfer heat to the battery module 16, a heat-conducting medium 34, i.e., a so-called gap filler material (Gap-Filler), can be additionally provided. The protective element 28 can be arranged between the cooling channels 32, which can be constructed, for example, as a material narrowing portion in the bottom of the battery housing 20. That is, the protective element 28 is arranged in the gap of the meandering cooling channel 32 and can be melted by the diffusion gas under diffusion conditions to provide an opening to the outside. In addition to the cooling effect on the battery cell 18, the cooling channel 32 also has a stabilizing effect. That is, the cooling channel provides additional mechanical protection for the battery module 16. In addition, the cooling channel 32 can be designed to cool the protective element 28 in the normal state of the power battery device 12. It can be additionally ensured that the protective element 28 will not be unstable under normal conditions and will not release the opening to the outside when the power battery device is running.

[0036] Overall, these exemplary embodiments show how a cost-effective, diffusion-resistant and sealed high-voltage battery module can be provided by means of the present invention.

Claims

1. A power battery device (12) for a vehicle (10), the power battery device having at least one battery module (16) and a battery housing (20), wherein the at least one battery module has at least one battery cell (18), and the at least one battery module (16) is arranged in the battery housing, wherein: The at least one battery cell (18) has a diffusion opening (26) for discharging diffusion gas from the battery cell (18), It is characterized in that At least one protective element (28) is provided in a battery housing wall of a battery housing (20), the at least one protective element being configured to collapse under the action of diffusion gas and to provide an opening through the battery housing wall for discharging diffusion gas from the power battery device (12), The corresponding protective element (28) is arranged opposite to the diffusion opening (26) of the corresponding battery cell (18), so that the diffusion opening of the battery cell is directly aligned with the battery housing wall having the corresponding protective element, so that the diffusion gas directly reaches the protective element after escaping from the battery cell and quickly penetrates the opening of the battery housing wall.

2. The power battery device (12) according to claim 1, wherein: The diffusion opening (26) and the corresponding protective element (28) are arranged toward the underside of the power battery device (12), wherein the underside of the power battery device (12) in a predetermined installation position particularly points toward the underside of the vehicle (10).

3. The power battery device (12) according to claim 1 or 2, wherein: The respective protective element (28) is designed as a material weakness of the battery housing wall, wherein the material weakness is designed to melt due to the temperature of the diffusion gas.

4. The power battery device (12) according to claim 3, wherein: The material weakness comprises a material with a predetermined melting point and / or a predetermined material thickness.

5. The power battery device (12) according to claim 1 or 2, wherein: The corresponding protective element (28) consists essentially of plastic.

6. The power battery device (12) according to claim 5, wherein: The battery housing wall comprises metal (30) which is designed to maintain the stability of the battery housing (20) and to protect the battery module (16) from mechanical damage, wherein the metal comprises at least one recess for at least one protective element (28) made of plastic.

7. The power battery device (12) according to claim 1 or 2, wherein: The battery housing (20) has cooling channels (32) on the side facing the battery module (16), which cooling channels are in particular designed to be meandering, wherein the protective element (28) is arranged in the gaps of the cooling channels.

8. The power battery device (12) according to claim 1 or 2, wherein: The battery module (16) is sealed to the outside by means of a potting material (22).

9. A motor vehicle (10) comprising a power battery device (12) according to any one of claims 1 to 8.

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