DE102021204370B4 - Accumulator arrangement for a motor vehicle and motor vehicle with an accumulator arrangement - Google Patents

Abstract

Accumulator arrangement (10) with an accumulator (12) for supplying an electric drive of a motor vehicle with electrical energy, the accumulator (12) having a gas-tight accumulator housing (16), the accumulator (12) having an emergency degassing device (18) for releasing gas from the interior of the gas-tight battery housing (16), the battery arrangement (10) having a protective element (14) to protect the battery (12) from mechanical damage in the event of a collision of the motor vehicle with an object and is designed to do so in the event an emergency degassing of the accumulator (12), the gas occurring inside the gas-tight area of the accumulator housing (16) is released via the emergency degassing device (18) into a cavity (20) formed by the protective element (14), characterized in that the accumulator (12 ) has a plurality of accumulator cells (24) arranged in the accumulator housing (16), which are designed to release gas accumulating in the cells (24) in a direction pointing away from the cavity (20).

Description

The invention relates to a battery arrangement with an accumulator for supplying an electric drive of a motor vehicle with electrical energy according to the preamble of claim 1 and a motor vehicle with such a battery arrangement.

In motor vehicles with electric drives, accumulators are used to supply the electric drive with energy. There is a risk that flammable gases will be produced in the event of defects in the accumulators. The accumulators therefore have gas-tight accumulator housings. The gas is initially produced in these accumulator housings.

In the case of serious defects that lead to a correspondingly large amount of released gas, the pressure and/or the temperature in the accumulator housing can reach a critical value. In this case, it makes sense to release the gas accumulating within the accumulator housing from the accumulator housing by means of an emergency degassing. For this purpose, modern accumulators have emergency degassing devices for releasing gas from the interior of the gas-tight accumulator housing.

The gases or gas mixtures produced in the accumulator housing are generally combustible. The gases can be ignited, for example, by sparks, in particular by electrical sparks. This represents a risk in particular if the battery housing is deformed in the event of an accident. In particular, short circuits and increased gas development can occur inside the accumulator. The short circuits can also create sparks that can ignite the gases. Therefore, attempts are made to integrate accumulators in motor vehicles in the motor vehicle in such a way that they are protected as well as possible in the event of collisions between the motor vehicle and objects, such as other motor vehicles, but also other obstacles.

If the accumulator is installed in a corresponding position, for example below the back seat of a motor vehicle, there is often the problem of handling the gases escaping via the emergency degassing device in the event of an emergency degassing in such a way that the people in the motor vehicle are not endangered.

There is a particular risk that such gases will ignite, thereby forming a kind of “burning jet”. If, for example, it is directed in a direction in which there are body parts of people, for example passengers in the back seat, serious injuries to people can occur due to the resulting concentrated flames. In the worst case scenario, a gas flame concentrated in this way can also be able to “burn through” interior paneling and/or body components that separate the accumulator from people. Such a scenario becomes particularly critical if it is a hybrid vehicle and emergency degassing leads to a corresponding gas flame that is directed in the direction of the fossil fuel tank.

There is a particular risk of such flames forming when the gases leave the gas-tight accumulator housing. This is particularly due to the fact that other hot components of damaged battery cells often escape with the gas. If the gases formed in the accumulator mix with the ambient air, this increases the risk that the gases will ignite - especially if these hot components are added, but also if other ignition sources, such as electrical devices, are present.

In the past, accumulators for motor vehicles have been developed in which design measures are intended to prevent such gas mixtures from igniting.

For example, in the DE 10 2019 118 905 A1 an accumulator is shown, in which gas occurring within a gas-tight accumulator can be cooled by means of an integrated cooling system when it emerges from one of the accumulator cells arranged in the accumulator housing within the accumulator housing.

In the US 2013/0059175 A1 An accumulator is described which has a collecting area within the gas-tight accumulator housing. This is arranged below the individual accumulator cells, so that when gas emerges from the individual accumulator cells into the gas-tight housing, it and any hot components that may be carried along with the gas are initially collected in a collection area.

The US 2022 0021068 A1 shows an accumulator in which a plurality of cells arranged in an accumulator housing release the gas towards a common gas collection chamber in the event of an emergency degassing.

The CN 2 09 401 662 U shows an accumulator in which a plurality in one accumulator Cells arranged in the housing release the gas towards a cavity in the event of an emergency degassing.

The DE 10 2014 213 916 A1 shows an accumulator in which a plurality of cells arranged in an accumulator housing release the gas towards a degassing collector in the event of an emergency degassing.

These systems are able to reduce the temperature of the gas within the gas-tight housing of the accumulator, so that the gas produced in the gas-tight housing has a low temperature, or other hot components that can serve as ignition sources can be retained . However, with such systems it can also happen that the pressure in the accumulator housing increases to such an extent that emergency degassing, in which the gas is released from the gas-tight housing, becomes necessary. In this case, the gas would have a lower temperature or contain fewer ignition sources due to the retained additional components of defective accumulator cells, but the gas emerging from the gas-tight accumulator housing could still form ignitable mixtures with the ambient air. These could certainly still be ignited by other ignition sources, which may be present in the motor vehicle or in its immediate surroundings, especially after an accident.

Furthermore, the systems described above have the disadvantage that cooling systems or collecting areas must be arranged within the gas-tight battery housing. This increases the volume of the gas-tight battery housing. However, a battery housing with a larger volume is less likely to be protected from mechanical damage in the event of an accident to the motor vehicle than a battery housing with correspondingly smaller dimensions.

The invention is based on the object of showing a battery arrangement with an accumulator for supplying an electric drive of a motor vehicle with electrical energy and a motor vehicle with such a battery arrangement, which enable safe emergency degassing and at the same time good protection of the gas-tight battery housing from possible mechanical damage.

The task is solved by a battery arrangement and a motor vehicle with the features of the independent claims. The dependent claims relate to advantageous embodiments.

The object is achieved in that the accumulator arrangement has a protective element to protect the accumulator from mechanical damage in the event of a collision of the motor vehicle with an object and is designed so that in the event of an emergency degassing of the accumulator, the gas occurring inside the gas-tight area of the accumulator housing is released via the emergency degassing device into a cavity formed by the protective element.

Protective elements that serve to protect the battery from mechanical damage, especially in the event of an accident of the motor vehicle, can be designed in such a way that they form a cavity. The cavity can only be limited by the protective element itself. Alternatively and/or, however, it is advantageous if the protective element only forms part of the boundary of the cavity. Where the cavity is not limited by the protective element, it can then be limited by other elements of the motor vehicle. In particular, elements of the accumulator itself can form part of the boundary of the cavity. In this way, favorable paths can be implemented for the escaping gas from the interior of the accumulator housing into the cavity.

A cavity formed in this way by a protective element represents an area of the motor vehicle in which the hot gas can initially collect and cool down. The cavity does not need to be closed. Basically, it is advantageous if the cavity has an opening to the environment through which the gas can leave the cavity. The opening can also be used for other purposes, for example as a water drainage opening. In this way, the cavity acts particularly as a “cooling zone”. Due to the limited volume of the cavity, only a certain amount of an ignitable mixture can form in it. If the gas released in the accumulator flows through the cavity during an emergency degassing, the cavity is essentially flushed through while the air is displaced, so that ignitable mixtures are only present in the cavity for a short period of time and in a limited amount. The gases can then cool down within the cavity before leaving it again and mixing with the surrounding air. Components that are dragged along with the escaping gas, which may be glowing components of the accumulator, can also cool in the cavity. Since protective elements to protect the accumulator from mechanical damage usually point in directions from which mechanical influences on the accumulator are to be expected in an accident, such a cavity, which is formed by a protective element, is usually arranged in an area of the motor vehicle in which deformations may take place in the event of an accident, for example in the immediate vicinity of the outer boundary surfaces of the motor vehicle. In particular, an outer boundary surface of the motor vehicle is formed by the protective element. A possible burning of the escaping gas within the cavity therefore typically takes place in an area in which there is no immediate danger to the occupants of the vehicle and/or sensitive structures that pose further dangers in the event of a fire.

In a motor vehicle, the protective element is arranged in particular on a side of the battery facing away from the passenger compartment and/or a fuel tank of the motor vehicle. In this way, the combustible gases released in the accumulator are released in a controlled manner in an area that is spatially separated from people and/or fuel. The accumulator with its gas-tight housing represents an additional barrier between the zone in which the released gases can burn off and the passengers to be protected or the fuel tank to be protected. Particularly if the accumulator has a flat design, this can be done advantageously ensure the protection of the occupants or the fuel.

The protective element can in particular be a sheet metal. A sheet is understood to mean any flat structure made of a metallic material, which can in particular be steel and/or an aluminum alloy. In addition to their mechanical stability and their good plastic deformation properties, such sheets have the advantage that they have good thermal conductivity and heat capacity. As a result, protective elements made of metallic materials are particularly well suited to cooling gas led into the cavity.

In this context, the protective element can be designed in particular as a trough. Using a trough shape, such a protective element can form a cavity together with a substantially flat area. This makes it possible to mount the protective element directly on a flat side of a battery.

At least one metallic crash element can be arranged within the cavity to absorb deformation energy in the event of a deformation of the protective element due to a collision of the motor vehicle with an object. The crash element can in particular be made of a metallic material, for example steel or an aluminum alloy. Furthermore, it is possible for a plurality of such crash elements to be arranged within the cavity.

Such crash elements serve to increase the amount of energy that can be dissipated by the deforming protective element in the event of a crash. In connection with the present invention, crash elements have the advantage that they form flow obstacles for the gas flowing through the cavity in the event of an emergency degassing. The resulting flow conditions allow the gas to release more heat in a shorter time compared to a direct flow through the cavity. Metallic crash elements are particularly advantageous in this context because, due to their heat capacity and thermal conductivity, they themselves absorb thermal energy to a certain extent and can thus actively contribute to cooling the gas.

In this context, the cavity in particular has an opening through which the gas can leave the cavity again. It goes without saying that the cavity can also have a plurality of openings. The opening can be, for example, an opening in the protective element. The opening is preferably arranged at a location in the cavity that is remote from the emergency degassing device. This ensures that the gas has to travel as far as possible as it flows through the cavity. Preferably, at least one crash element described above is arranged on the flow path from the emergency degassing device to the opening. In this way it is ensured that the gas actually flows into the crash elements. The crash elements can be, for example, angled sheet metal parts, in particular trapezoidal sheets. Crash elements designed in this way provide a plurality of flat areas to which the gas can flow, which are well suited to absorb thermal energy from the gas and also represent a barrier for hot components of the accumulator that are carried along with the gas flow.

The accumulator has a plurality of accumulator cells arranged in the accumulator housing. The accumulator cells each have cell degassing devices through which gas occurring in the individual accumulator cells is released into the interior of the gas-tight accumulator housing. In this context, the accumulator cells are arranged in such a way that the degassing of the accumulator cells into the gas-tight Housing takes place in a direction pointing away from the cavity. In this way, the hot gas must first be conducted in an arc in the gas-tight housing before the gas-tight housing can leave in the direction of the cavity through the emergency degassing device. This has the advantage that the gas, which emerges from the accumulator cells when hot and thereby possibly transports hot material from the interior of the accumulator cells, has already traveled a comparatively long distance before it enters the cavity, which means that the temperature of the gas has already increased could lower. In addition, hot components of the accumulator cells that are dragged along can already cool down on the gas's path to the emergency degassing device and/or can even be separated from the gas stream if they get caught within the gas-tight accumulator housing and are therefore no longer dragged along.

The accumulator can have a reinforcing element for mechanically reinforcing the accumulator. The reinforcing element can in particular be connected to the gas-tight battery housing. As a result, the reinforcing element can help prevent deformation of the gas-tight battery housing, particularly in the event of serious accidents.

The reinforcing element can be a flat reinforcing element. A flat reinforcing element offers the particular advantage that it can offer good reinforcement in its plane - particularly if the reinforcing element is arranged parallel to the main extension directions of the accumulator. In particular, if the reinforcing element or the accumulator is arranged horizontally in the motor vehicle with its main extension directions, the reinforcing element can effectively protect the accumulator in accidents in which the motor vehicle is hit from the side. In this context, the main extension directions are to be understood in particular as meaning the directions in which the accumulator has its greatest extent.

The reinforcing element can be a sheet metal, in particular made of steel and/or an aluminum alloy.

The reinforcing element is preferably arranged between the gas-tight battery housing and the cavity. In this arrangement, the reinforcing element can serve to limit the cavity. This is particularly advantageous if the reinforcing element is a reinforcing element made of a metallic material, since the reinforcing element is then suitable for extracting thermal energy from the hot gases flowing into the cavity due to its heat capacity and thermal conductivity.

The emergency degassing device can be passed through the reinforcing element and connect the interior of the gas-tight accumulator housing to the cavity. In such a configuration, the emergency degassing device offers in particular a feedthrough in the manner of a short line section that bridges the distance from the inside of the gas-tight accumulator housing to the inside of the cavity. For this purpose, the emergency degassing device can in particular be connected in a gas-tight manner to the gas-tight accumulator housing. The connection between the emergency degassing device and the accumulator housing can be, for example, a cohesive connection, in particular a soldered connection.

The emergency degassing device can also be connected to the reinforcing element. The connection to the reinforcing element can be a positive connection, in particular a clip and/or snap connection. This enables easy installation of the emergency degassing device. In particular, the emergency degassing device can be designed in several parts. Different parts of the emergency degassing device can each be connected to the gas-tight housing of the accumulator or the reinforcing element. In particular, it is conceivable that a support element for a membrane, which in the case of an emergency degassing device opens the gas path for the gas emerging from the housing via the emergency degassing device, can be part of the emergency degassing device. In this context, a further advantage is that the membrane can be protected by the protective element from mechanical impairments that occur during operation of the motor vehicle, such as dirt. The carrier element can in particular be connected to an element of the emergency degassing device which is connected to the gas-tight housing. A seal can be provided between these two elements. A further holding element of the emergency degassing device connected to the carrier element can secure the carrier element in its intended position. Such an emergency degassing device can be installed particularly easily.

In the case of a motor vehicle with a battery arrangement according to the above description, the protective element can in particular be a protective element arranged in the area of the underbody of the motor vehicle act. In particular, it can be a collision protection element to protect the battery when it hits an obstacle. Such collision protection elements are also referred to as “bollard protection”. In this context, the battery can preferably be arranged in the area of the underbody of the motor vehicle, in particular below the rear seat. The main extension directions of the gas-tight battery housing are preferably oriented parallel to the horizontal axes of the motor vehicle. Such an arrangement of the battery is favorable in terms of the available installation space and the resulting center of gravity of the motor vehicle. The high risk that the battery will be damaged when driving over an obstacle or hitting an obstacle, which in practice can lead to high repair costs, can be effectively prevented by a protective element designed as a collision protection element. At the same time, the collision protection element in connection with the present invention can provide a suitable cavity into which the gas can be released via the emergency degassing device.

Consequently, it is particularly advantageous if the cavity is arranged below the accumulator. Particularly in connection with an upward emergency degassing of the individual accumulator cells into the interior of the gas-tight accumulator housing, this results in the desired long gas paths, which ensure good cooling of the gas in the event of an emergency degassing and thus minimize the risk of fire. At the same time, good protection of the battery against mechanical damage is guaranteed.

• 1 eine Schnittdarstellung durch eine beispielhafte Akkumulatoranordnung,
• 2 eine Detaildarstellung der Schnittdarstellung in 1 im Bereich der Notentgasungseinrichtung,
• 3 eine Darstellung eines beispielhaften Schutzelements mit zusätzlichen Crashelement.

Further practical embodiments of the invention are described below in connection with the drawings. Show it:

• 1 a sectional view through an exemplary accumulator arrangement,
• 2 a detailed representation of the sectional view in 1 in the area of the emergency degassing device,
• 3 a representation of an exemplary protective element with an additional crash element.

The battery arrangement 10 shown as an example has a battery 12 and a protective element 14. The accumulator 12 has a gas-tight accumulator housing 16. The accumulator arrangement 10 shown as an example is designed so that in the event of an emergency degassing of the accumulator 12, the gas occurring inside the gas-tight region of the accumulator housing 16 is released via the emergency degassing device 18 into a cavity 20 formed by the protective element 14.

The reinforcing element 14 can - as in 3 can be seen in particular - have an opening 21 through which the gas can exit the cavity 20 again.

The protective element 14 can be a trough-shaped sheet metal, as in the example shown. This is particularly evident in the perspective view of the protective element 14 in the 3 to recognize.

As in the example shown, a metallic crash element 22 can be arranged within the cavity 20. The crash element 22 can be a sheet metal, as in the example shown. The crash element 22 can have flat areas, as in the example shown. In particular, as in the example shown, it can be a sheet metal which has areas that are angled relative to one another. In the example shown, the crash element 22 is, for example, a trapezoidal sheet metal.

The gas occurring inside the accumulator housing 16 can come in particular from an accumulator cell 24 arranged inside the gas-tight housing 16. The accumulator 12 can in particular have a plurality of accumulator cells 24 arranged inside the gas-tight housing 16. Due to the chosen perspective and cutting plane, only one of them is visible in the figures. The individual accumulator cells 24 can in particular be designed in such a way that gas occurring inside the accumulator cell 24 initially flows upwards, i.e. H. from which is emitted in the direction pointing away from the protective element 14. In the case of an emergency degassing via the emergency degassing device 18, the gas in the example shown initially flows on the side of the accumulator cells 24 facing away from the protective element 14 within the accumulator housing 16 into a lateral region 26 of the accumulator housing 16 and from there through the emergency degassing device 18 into the cavity 20.

The accumulator 12 may have a reinforcing element 28. This can be designed as a metal plate as in the example shown. In this case, it is particularly advantageous if the reinforcing element 28 is arranged between the gas-tight battery housing 16 and the cavity 20. As in the example shown, the reinforcing element 28 can limit the cavity 20 towards the battery housing 16.

The accumulator 12 can have a cooling device for cooling the accumulator housing 16 point. This can, as in the example shown, have a cooling element 30. The cooling element 30 can be designed flat as shown. Preferably, the cooling element 30 corresponds to the exemplary illustration in the 1 and 2 between the cavity 20 and the battery housing 16, in particular between the reinforcing element 28 and the battery housing 16. The accumulator arrangement 10 can have a coolant connection 32 for supplying the cooling device with a coolant.

Like in particular 2 clearly visible, the emergency degassing device 18 can be guided through the reinforcing element 28. As in the case shown, the emergency degassing device 18 can have an element 34 connected in a gas-tight manner to the gas-tight housing 16. A carrier element 36 that carries a membrane 38 can be inserted into the element 34. The membrane 38 is designed, in particular, to open the gas path through the emergency degassing device 18 when the pressure and/or temperature increases beyond a critical level, for example by causing the membrane to rupture and/or melt. This is particularly in 2 shown.

A seal 40 can be arranged between the carrier element 36 and the element 34 of the emergency degassing device 18 connected to the gas-tight housing 16 and ensure a seal between the element 34 and the carrier element 36. As in the example shown, the carrier element 36 can be fixed in its intended position by means of a holding element 42. As shown, the holding element 42 can be fixed to the reinforcing element 28. The fixation can be done by a snap connection, as shown in the example.

The battery arrangement 10 shown as an example is arranged in a motor vehicle in particular in such a way that the cavity 20 is arranged below the battery 12.

Thus, the protective element 14, as in the case of the protective element 14 shown as an example, can be a collision protection element arranged in the area of the underbody of the motor vehicle to protect the battery 12 when it hits an obstacle.

Advantageously, an accumulator arrangement 10 such as the one shown by way of example can be arranged in a motor vehicle with an accumulator arrangement 10 in such a way that the cavity 20 is arranged on a side of the accumulator 12 facing away from the passenger compartment and/or a fuel tank of the vehicle. In this way it is ensured that the combustible gases that are directed towards the cavity 20 are directed away from the passenger compartment and/or the fuel tank of the motor vehicle in order to cool down.

The features of the invention disclosed in the present description, in the drawings and in the claims can be essential for the implementation of the invention in its various embodiments, both individually and in any combination. The invention can be varied within the scope of the claims and taking into account the knowledge of the responsible person skilled in the art.

Reference symbol list

10

Accumulator arrangement

12

accumulator

14

Protective element

16

Accumulator housing

18

Emergency degassing device

20

cavity

21

opening

22

Crash element

24

Accumulator cell

26

Area of the battery housing

28

Reinforcement element

30

Cooling element

32

Coolant connection

34

element

36

Support element

38

membrane

40

poetry

42

Holding element

Claims (9)

Accumulator arrangement (10) with an accumulator (12) for supplying an electric drive of a motor vehicle with electrical energy, the accumulator (12) having a gas-tight accumulator housing (16), the accumulator (12) having an emergency degassing device (18) for releasing gas from the interior of the gas-tight battery housing (16), the battery arrangement (10) having a protective element (14) to protect the battery (12) from mechanical damage in the event of a collision of the motor vehicle with an object and is designed to do so in the event an emergency degassing of the accumulator (12), the gas occurring inside the gas-tight area of the accumulator housing (16) is released via the emergency degassing device (18) into a cavity (20) formed by the protective element (14), characterized in that the accumulator (12 ) has a plurality of accumulator cells (24) arranged in the accumulator housing (16), which are designed to release gas accumulating in the cells (24) in a direction pointing away from the cavity (20). Accumulator arrangement (10). Claim 1 , characterized in that the protective element (14) is a trough-shaped sheet metal. Accumulator arrangement (10). Claim 1 or 2 , characterized in that at least one metallic crash element (22) is arranged within the cavity (20) to absorb deformation energy in the event of a deformation of the protective element (14) due to a collision of the motor vehicle with an object. Accumulator arrangement (10) according to one of the preceding claims, characterized in that the accumulator (12) has a reinforcing element (28) for mechanically reinforcing the accumulator (12), which is connected to the gas-tight accumulator housing (16). Accumulator arrangement (10). Claim 4 , characterized in that the reinforcing element (28) is arranged between the gas-tight battery housing (16) and the cavity (20) and delimits the cavity (20) towards the battery housing (16). Accumulator arrangement (10). Claim 4 or 5 , characterized in that the emergency degassing device (18) is passed through the reinforcing element (28) and connects the interior of the accumulator housing (16) with the cavity (20). Accumulator arrangement (10) according to one of the preceding claims, characterized in that the protective element (14) has an opening through which the gas released into the cavity (20) in the event of an emergency degassing can leave the cavity (20). Motor vehicle with a battery arrangement (10) according to one of the preceding claims, characterized in that the protective element (14) is a collision protection element arranged in the area of the underbody of the motor vehicle to protect the battery (12) when hitting an obstacle. motor vehicle Claim 8 or with an accumulator arrangement (10) according to one of the Claims 1 until 7 , characterized in that the cavity (20) is arranged on a side of the accumulator (12) facing away from the passenger compartment and/or a fuel tank of the motor vehicle.

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