DE102019203606A1 - Battery module and motor vehicle - Google Patents

Abstract

A battery module (1) according to the invention, in particular for a motor vehicle (50), has a module housing (2) which comprises an elongated box-like hollow profile (4) which in turn has a cell chamber (8) for mechanically protective accommodation of a plurality of battery cells (10) ) delimited in four spatial directions. The cell chamber (8) is sealed media-tight when the battery module (1) is used as intended. A pressure outlet opening (34) introduced into at least one wall (6, 16, 20) of the module housing (2) delimiting the cell chamber (8) is closed by a pressure relief valve (32) that opens unidirectionally away from the cell chamber (8).

Description

The invention relates to a battery module, in particular for a motor vehicle, and to a motor vehicle with such a battery module.

Battery modules are used in particular in electric motor vehicles to accommodate a plurality of battery cells, to interconnect them and to feed the corresponding output voltage to an on-board network of the motor vehicle. Battery modules are often also set up to protect the battery cells from mechanical influences, for example impact forces in the event of an accident, and / or the ingress of moisture. In order to be able to accommodate as many battery cells as possible in the motor vehicle, which is conducive to high driving performance, it is expedient to make the associated, mechanically protective housings as small as possible. This in turn has the disadvantage that if a battery cell fails, media, for example electrolyte liquid and / or smoke gases, often escape from it. Since these media often also contain soot, other battery cells can be damaged by contact with the media, which could trigger a chain reaction (also known as “thermal runaway”).

The invention is based on the object of increasing the safety of a battery module.

This object is achieved according to the invention by a battery module with the features of claim 1. Furthermore, this object is achieved according to the invention by a motor vehicle with the features of claim 11. Further advantageous and in part inventive embodiments and developments of the invention are in the dependent claims and the the following description.

The battery module according to the invention is preferably set up and provided for use in a (preferably land-based) motor vehicle. The battery module includes a module housing which has an elongated, box-like hollow profile. This hollow profile in turn delimits a cell chamber which is set up for mechanical protective accommodation of a plurality of battery cells, at least in four spatial directions, which are preferably in pairs perpendicular to one another and perpendicular to the longitudinal extent of the hollow profile. The cell chamber is sealed media-tight when the battery module is in its intended use. In addition, at least one wall of the module housing that delimits the cell chamber is provided with at least one pressure outlet opening, which in turn is closed by an overpressure valve that opens unidirectionally away from the cell chamber.

The “intended use state” of the battery module is understood here and in the following in particular to mean the state in which the battery module is installed in the motor vehicle. Preferably, however, the state prior to installation in the motor vehicle in which the battery module with all its components, in particular the battery cells, contacts, possibly a charge and / or discharge control or the like, is properly equipped, is understood as the intended use state. Thus, when the battery module is in the intended use state, a plurality of battery cells are preferably inserted into the cell chamber.

Furthermore, the battery module preferably forms part of a battery unit of the motor vehicle, with a plurality of structurally identical battery modules preferably being contained together in the battery unit.

The fact that the cell chamber, which is basically sealed against media, is provided with an overpressure valve, advantageously enables degassing of the cell chamber and thus reduces the risk that further battery cells (in particular those in another cell chamber) are damaged due to the medium escaping from the damaged battery cell. Due to the unidirectional opening of the overpressure valve, it is also advantageously prevented that, in the event of locally occurring overpressure, ambient media located directly in the area around the battery module, or in the worst case, media escaping from a surrounding battery module, can penetrate the battery module via the overpressure valve.

In a preferred embodiment, the cell chamber is delimited by at least three outer walls of the hollow profile that run in the longitudinal direction. I.e. these three outer walls of the hollow profile delimit the cell chamber from the surroundings of the battery module. The module housing preferably represents a load-bearing (“structural”) element of the battery module, which serves to absorb and dissipate (or forward) forces acting on the battery module. In this case, the three outer walls of the hollow profile are preferably also set up and provided for receiving and dissipating acting loads. More preferably, the outer walls run with their longitudinal direction in the intended installation state in the motor vehicle along a vehicle transverse direction, which is also referred to below as the Y direction. The three outer walls preferably form a U-shaped partial profile of the hollow profile, which is recognized for Absorption of forces in the Y direction, in the X direction and in the Z direction is formed.

The hollow profile is preferably formed by an extruded profile, preferably made of aluminum.

In an expedient embodiment, the cell chamber is, at least in the intended use state, closed transversely to the longitudinal direction of the hollow profile by an end cover - preferably on both end faces of the hollow profile with an end cover each. The respective end cover therefore also forms a wall that closes the cell chamber in a further spatial direction (perpendicular to the previous ones). This end cover is preferably also made of aluminum and welded to the hollow profile, preferably by means of laser beam welding.

In a preferred development of at least one of the two embodiments described above, the hollow profile has a support chamber running parallel to the cell chamber and preferably delimited to the outside by means of three longitudinal walls on an underside facing the underside of the motor vehicle in the intended use state. This support chamber is separated from the cell chamber by means of a partition wall that carries fewer forces compared to the longitudinal walls and the outer walls. This support chamber, specifically its longitudinal walls, preferably forms an underrun protection integrated into the battery module, i. H. a kind of crumple zone for impact forces that act on the battery module from the underside.

In a variant that is fundamentally conceivable within the scope of the invention, the pressure outlet opening is arranged in a wall that delimits the cell chamber towards the surroundings - in particular in one of the outer walls and / or in at least one of the optionally multiple end covers. As a result, the media escaping in the event of damage are carried away as quickly as possible from the cell chamber and thus the battery cells contained therein.

In a preferred development of the embodiment described above, in which the module housing has the cell chamber and the support chamber, the pressure outlet opening closed by the pressure relief valve is arranged in the partition between the cell chamber and the support chamber. As a result, the support chamber, which, as described above, runs in particular parallel to the cell chamber, forms a guide or discharge channel for the media flowing out of the cell chamber in the event of damage. Since the support chamber preferably also represents a channel that is closed transversely to its longitudinal extension, the media emerging from the cell chamber can thus be diverted to the end faces of the hollow profile and thus of the module housing without coming into contact with cell chambers of adjacent battery modules and / or their battery cells. In addition, the partition wall is the wall of the hollow profile with the least structural requirements. I.e. the partition wall is advantageously not in the direct load path along the hollow profile in the event of an impact on the battery module. The partition wall therefore expediently also has a wall thickness that is reduced in comparison to the outer and the longitudinal walls of the hollow profile. The arrangement of the pressure outlet opening in this partition wall advantageously only leads to a negligible weakening of the mechanical structure of the module housing.

Regardless of the positioning of the pressure outlet opening, it preferably has a circular or at least oval cross section. This reduces stress peaks in the respective wall carrying the pressure outlet opening.

In a preferred embodiment, preferably for the case that the pressure outlet opening is arranged in the partition wall towards the support chamber, the support chamber is closed at the end by a further shut-off valve opening unidirectionally towards the environment. The support chamber is preferably closed on both of its (front) sides by such a closing valve. This advantageously prevents the penetration of ambient media such as moisture, mud or the like, which could possibly lead to the support chamber being closed. Due to the shut-off valve, the patency of the support chamber is maintained. The closing valve is preferably dimensioned in such a way that the closing valve also opens in the event of a pressure increase in the support chamber due to the entry of battery media through the pressure outlet opening. As a result, the media emerging from the cell chamber can still be diverted to the environment. Optionally, however, it is also possible that the respective shut-off valve only opens when there is a significantly excessive overpressure in the support chamber, so that a certain pressure equalization between the cell chamber is made possible, for example, in the event of a comparatively minor damage case in the cell chamber that just leads to the overpressure valve opening without any media that has already escaped having to be drained into the environment.

In a further useful embodiment, the pressure relief valve is designed as a one-way valve. This simplifies, for example, a visual check of the state of the respective cell chamber, since a triggered overpressure valve indicates a case of damage within the cell chamber, so that it should no longer be operated. As an alternative or in addition, the shut-off valve which may be present is preferably also designed as such a one-way valve.

In a further preferred embodiment, preferably in the case that the pressure relief valve and / or the possibly existing shut-off valve is designed as a one-way valve, the overpressure valve and / or the shut-off valve has a plug which in turn has a conical or at least pyramidal geometry. When used as intended, this sealing plug is inserted with its tapered end in the direction of the cell chamber into the pressure outlet opening or in the direction of the support chamber into the corresponding outlet opening of the support chamber. In other words, the corresponding sealing plug is inserted into the pressure outlet opening or outlet opening from the outside of the respective chamber. Because of the conical or pyramidal geometry, it is advantageous here to prevent the sealing plug from being pushed through the pressure outlet opening or the outlet opening into the corresponding chamber located behind it. Thus, in the event of a pressure release from an adjacent cell chamber, which occurs at least locally in the vicinity of the pressure outlet opening of this cell chamber, penetration of the media emerging from the adjacent cell chamber through the closed pressure outlet opening can be prevented. In a preferred variant, the respective closure plug has the conical geometry, since the pressure outlet opening is also preferably circular.

In particular in the event that the pressure outlet opening is arranged in the partition between the support chamber and the cell chamber and is therefore closed by the sealing plug, the sealing plug is in an expedient embodiment through a temporary assembly opening in the underside longitudinal wall - also referred to as the bottom wall - of the support chamber the pressure outlet is inserted. The temporary assembly opening is preferably tightly closed after assembly of the closure plug, for example welded by means of a cover.

In an optional variant, the sealing plug is preferably formed by a - in particular closed-pore - foam, which is compressed for assembly and thus brought into an approximately cylindrical shape and then inserted from the inside of the cell chamber through the pressure outlet opening in the direction of the support chamber. The closure plug then expands - for example due to a memory effect, the action of heat and / or the like - so that it again assumes its conical (or pyramidal) geometry. Optionally, the sealing plug is also hardened after its assembly, for example cross-linked, so that it is prevented from being deformed back into a structure in which it would fit through the pressure outlet opening. Preferably, however, the expansion caused by the elastic and / or the memory effect is already sufficient to produce a sufficient sealing effect in the direction of the “own” cell chamber even in the case of degassing of an adjacent cell chamber.

In a further expedient embodiment, the cell chamber of the module housing is divided into two longitudinally separated sub-chambers by a connection block which is used to contact the battery cells in the cell chamber with a superordinate network - in particular a vehicle electrical system. This is particularly useful to the extent that the battery module and thus also the module housing preferably extend over approximately the entire width of the vehicle in the intended installation state. However, the battery cells usually do not usually have such a large longitudinal extent. By dividing the cell chamber, wiring costs, i.e. H. in particular, a lead-through of conductor tracks for making contact with all battery cells arranged in the cell chamber can be reduced over the entire length of the module housing. In addition, this also enables contact to be made with the vehicle electrical system in the particularly safest area of the vehicle, namely its center. In this case, each of these sub-chambers formed by the connection block is preferably assigned a corresponding pressure outlet opening and a correspondingly assigned pressure relief valve.

The motor vehicle according to the invention has at least one battery module of the type described above. Preferably, however, the motor vehicle has a plurality, i. H. at least two of these battery modules, which are preferably arranged parallel to one another and transversely to the longitudinal extent of the vehicle (i.e. in the transverse direction of the vehicle).

The conjunction “and / or” is to be understood here and in the following in particular in such a way that the features linked by means of this conjunction can be designed both together and as alternatives to one another.

• 1 in einer schematischen, aufgebrochenen Perspektivansicht ein Batteriemodul,
• 2 in einem schematischen Querschnitt ein Hohlprofil, das ein Modulgehäuse des Batteriemoduls bildet,
• 3 in einem schematischen Längsschnitt III-III gemäß 2 das Batteriemodul,
• 4-8 jeweils in Ansicht gemäß 3 ein weiteres Ausführungsbeispiel des Batteriemoduls,
• 9 in Ansicht gemäß 2 wiederum ein weiteres Ausführungsbeispiel des Batteriemoduls, und
• 10 in einer schematischen Seitenansicht ein Kraftfahrzeug.

Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. Show in it:

• 1 a schematic, broken perspective view of a battery module,
• 2 in a schematic cross section a hollow profile which forms a module housing of the battery module,
• 3 in a schematic longitudinal section III-III according to 2 the battery module,
• 4-8 each in view according to 3 another embodiment of the battery module,
• 9 in view according to 2 again another embodiment of the battery module, and
• 10 in a schematic side view a motor vehicle.

Corresponding parts are always provided with the same reference symbols in all figures.

In 1 is schematically a battery module 1 shown. This includes a module housing shown in more detail below 2 . This is in 1 shown broken. The module housing 2 is through a hollow profile 4th , shown in 2 , educated. The hollow profile 4th bordered with three outer walls 6th that form a U-profile, a cell chamber 8th , in which in the intended use state (compare 1 ) several battery cells 10 are arranged. The underside is adjacent to the cell chamber 8th one to the outside of three longitudinal walls 12th enclosed support chamber 14th on. The cell chamber 8th and the support chamber 14th are thereby through a partition 16 separated from each other. In an optional variant of the exemplary embodiment, the longitudinal walls are used for further stiffening 12th in the support chamber 14th two diagonally arranged support walls 18th moved in.

The hollow profile 4th is specifically formed by an elongated and box-like shaped aluminum extrusion profile. In addition, the hollow profile represents 4th a structural component that can absorb and divert (or forward) loads - for example in the event of a crash. The walls essentially lying in the force flow are the outer walls 6th as well as the longitudinal walls 12th . The outside walls 6th as well as the longitudinal end 12th therefore point towards the partition 16 an increased wall thickness. The cell chamber 8th is in the intended use condition of the battery module 1 frontal, ie transversely to the longitudinal extension of the outer walls 6th through a cover plate each 20th tightly closed. The end cover is specific 20th on the hollow profile 4th welded on. This puts them in the cell chamber 8th arranged battery cells 10 protected from environmental influences.

The cell chamber 8th is also in two sub-chambers 22nd divided that lengthways 24 of the module housing 2 seen successive. For subdivision is in the cell chamber 8th a connection block 26th arranged on which the corresponding poles of the battery cells 10 by means of conductor tracks 28 are merged. From the connection block 26th are corresponding connection contacts 30th to the outside of the battery module 4th , specifically the hollow profile 4th guided.

In the event of a short circuit in one of the battery cells, for example 10 the medium escaping in this case (usually gas, smoke and / or electrolyte liquid) from the cell chamber 8th , specifically the corresponding sub-chamber 22nd to be able to derive, is the cell chamber 8th or the corresponding sub-chamber 22nd with a pressure relief valve 32 Mistake. This closes unidirectionally from the cell chamber 8th opening one into one of the cell chambers 8th bordering walls introduced pressure outlet opening 34 .

In the embodiment according to 3 is the pressure outlet 34 in the partition 16 arranged and thus opens the cell chamber if necessary 8th into the support chamber 14th inside. That from the corresponding battery cell 10 Any medium that escapes (specifically smoke gases) is thus targeted via the support chamber 14th , which in this case forms a discharge channel, to the front sides of the battery module 1 discharged.

The pressure relief valve 32 has a sealing plug 36 on, which is conically shaped and with its tapered end into the pressure outlet opening 34 is used. This will prevent the pressure relief valve 32 even with increased ambient pressure in the cell chamber 8th opens into it. In addition, the sealing plug forms 36 the pressure relief valve 32 to a one-way valve.

In 4th is an opposite 3 further developed embodiment shown. The support chamber has therein 14th one outlet opening at each end 38 on, which in the intended use state by a shut-off valve 40 is locked. The closing valve 40 includes a plug 42 which is comparable to the sealing plug 36 of the pressure relief valve 34 is at least approximately tapered. Through this stopper 42 prevents the battery module from operating as intended 1 in a motor vehicle 50 (see 10 ) Media from the environment, in particular contamination in the support chamber 14th can penetrate.

In 5 and 6th are two further exemplary embodiments of the exemplary embodiments according to FIG 3 or. 4th shown. In both exemplary embodiments it is analogous to the connection block 26th a barrier 44 into the support chamber 14th pulled in, so that the support chamber 14th in two sub-chambers 46 is divided.

In the 7-9 further alternative embodiments are shown. In 7th are the pressure outlet openings 32 in the end caps 20th arranged. In 8th and 9 are the pressure outlet openings 32 in the outer walls 6th arranged.

In 10 is schematically the aforementioned motor vehicle 50 shown. The car 50 includes an electric prime mover 52 that are used to supply energy via an on-board network 54 with a plurality of the battery modules described above 1 is coupled.

The subject matter of the invention is not limited to the exemplary embodiments described above. Rather, further embodiments of the invention can be derived from the above description by a person skilled in the art. In particular, the individual features of the invention described on the basis of the various exemplary embodiments and their design variants can also be combined with one another in other ways.

List of reference symbols

1

Battery module

2

Module housing

4th

Hollow profile

6th

Outer wall

8th

Cell chamber

10

Battery cell

12

Longitudinal wall

14th

Support chamber

16

partition wall

18th

Retaining wall

20th

End cover

22nd

Subchamber

24

Longitudinal direction

26th

Connection block

28

Track

30th

Connection contact

32

Pressure relief valve

34

Pressure outlet

36

Sealing plug

38

Outlet opening

40

Shut-off valve

42

Sealing plug

44

barrier

46

Subchamber

50

Motor vehicle

52

Power machine

54

Electrical system

Claims (11)

Battery module (1), in particular for a motor vehicle (50), with a module housing (2) which comprises an elongated box-like hollow profile (4) which in turn has a cell chamber (8) for mechanically protective accommodation of a plurality of battery cells (10) in four Spatial directions, where - The cell chamber (8) is sealed in a media-tight manner when the battery module (1) is in its intended use, and - A pressure outlet opening (34) introduced into at least one wall (6, 16, 20) of the module housing (2) delimiting the cell chamber (8) is closed by a pressure relief valve (32) that opens unidirectionally away from the cell chamber (8). Battery module (1) Claim 1 wherein the cell chamber (8) is delimited by at least three outer walls (6) of the hollow profile (4) running in the longitudinal direction (24). Battery module (1) Claim 1 or 2 , the cell chamber (8) being closed transversely to the longitudinal direction (24) of the hollow profile (4) by a cover (20). Battery module (1) Claim 2 or 3 , the hollow profile (4) having, on an underside facing the underside of the motor vehicle (50) in the intended use state, a support chamber (14) running parallel to the cell chamber (8) and delimited to the outside by means of three longitudinal walls (12) which to the longitudinal walls (12) and the outer walls (6) less force-bearing partition (16) is separated from the cell chamber (8). Battery module (1) Claim 4 wherein the pressure outlet opening (34) closed by the pressure relief valve (32) is arranged in the partition wall (16) between the cell chamber (8) and the support chamber (14). Battery module (1) Claim 5 , the support chamber (14) at the front by a further, unidirectional to the environment opening shutoff valve (40) is closed. Battery module (1) according to one of the Claims 1 to 6th , the overpressure valve (32) and / or the possibly existing shut-off valve (40) being designed as a one-way valve. Battery module (1) according to one of the Claims 1 to 7th , wherein the pressure relief valve (32) and / or the possibly existing shut-off valve (40) has a sealing plug (36, 42) with a conical or pyramidal geometry, which with its tapered end in the direction of the cell chamber (8) into the pressure outlet opening (32) or in the direction of the support chamber (14) into an outlet opening (38) of the support chamber (14). Battery module (1) after a Claim 8 wherein the sealing plug (36) of the pressure relief valve (32) is inserted into the pressure outlet opening (32) through a temporary assembly opening in the underside longitudinal wall (12). Battery module (1) according to one of the Claims 1 to 9 , the cell chamber (8) being divided into two longitudinally separated sub-chambers (22) by a connection block (26) for contacting the accommodated battery cells (10) with a superordinate network (54) and each sub-chamber (22) having a pressure outlet opening ( 34) and an associated pressure relief valve (32) are assigned. Motor vehicle (50) with at least one battery module (1) according to one of the Claims 1 to 10 .

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