Battery system for a motor vehicle that is at least partially electrically powered

Abstract

Battery assembly (1) for a motor vehicle that is at least partially electrically powered, comprising battery cells (3) each with a cell degassing opening (13) and a housing assembly (2) with a housing wall (22) defining a housing space (12) and having housing degassing openings. A sealing assembly (40) with sealing elements (4) is arranged between the battery cells (3) and the housing wall (22). The sealing elements (4) can be moved from an assembly state (14) to a finished state (24), in which they provide their sealing effect, by releasing a pre-tensioned pre-tensioning device (5). The sealing elements (4) can be secured in the assembly state (14) by means of a fixing device (6). By selectively acting on the fixing device (6), the pre-tensioning device (5) can be released and the sealing elements (4) can be moved into the finished state (24).

Description

[0001] The present invention relates to a battery device for an at least partially electrically powered motor vehicle. The battery device comprises battery cells, each with at least one cell venting opening for discharging gases in the event of thermal runaway of the battery cell, and at least one housing device. The housing device has at least one housing space and a housing wall defining the housing space, which has housing venting openings. The housing venting openings are each arranged, at least in sections, opposite at least one of the cell venting openings.

[0002] In the event of a malfunction, such as a thermal runaway (or thermal event) of the battery cells, a large amount of gas is typically generated, which must be vented from the battery cells and the housing. To prevent the uncontrolled spread of gases within the housing, the housing vents are connected to their corresponding cell vents via vent connections sealed to the housing. For example, sealing devices are used for this purpose, which seal each of the vent connections with a sealing element.

[0003] Reliable sealing of the venting connections and the housing venting openings themselves is particularly important for battery systems in which the battery cells in the housing are directly surrounded by a cooling medium (so-called direct cooling). However, sealing the individual venting connections usually involves a very high installation effort.

[0004] It is therefore the object of the present invention to provide a battery device which offers a reliable seal of the degassing connections with respect to the housing space and at the same time can be installed as simply and economically as possible.

[0005] This object is achieved by a battery device having the features of claim 1. Preferred developments of the invention are the subject of the subclaims. Further advantages and features of the present invention will become apparent from the general description and the description of the exemplary embodiment.

[0006] The battery device according to the invention is for an at least partially electrically powered motor vehicle, and preferably for a passenger car. The battery device is designed in particular as a high-voltage battery and preferably as a traction battery. The battery device comprises battery cells, each with at least one cell venting opening for discharging gases in the event of thermal runaway of the battery cell. The battery device comprises at least one housing device with at least one housing space and with at least one housing wall delimiting the housing space. The housing wall has housing venting openings, which are each arranged at least partially opposite at least one of the cell venting openings. A sealing device with sealing elements is arranged between the battery cells and the venting connection.The sealing elements each seal at least one housing vent opening with the at least one opposite cell vent opening towards the housing space. In particular, this results in vent connections that are sealed (fluid-tight) with respect to the housing space. The sealing elements (each) can be converted from an assembled state (in which the sealing elements do not provide their sealing effect) to a finished state by relaxing at least one prestressed prestressing device. In the finished state, the sealing elements provide their sealing effect. The sealing elements (each) can be secured in the assembled state by means of at least one fixing device. In particular, the prestressing device can also be secured in the prestressed state by means of the fixing device. In particular, the sealing elements are prevented from undesirably leaving the assembled state by means of the fixing device.By selectively acting on the fixing device, the pre-tensioning device can be at least partially released (unloaded). In particular, this allows the sealing elements to be converted into the finished state. In particular, the pre-tensioning device is suitable and designed to convert (deform) the sealing elements from the assembled state to the finished state by releasing the pre-tensioning device.

[0007] The battery device according to the invention offers many advantages. A significant advantage is the sealing device with its sealing elements, pretensioning device, and fixing device. This allows the battery cells to be arranged in the housing space easily and without risk of damage to the sealing device and the battery cells. Furthermore, the sealing device provides reliable and at the same time inexpensive sealing of the venting connections and can therefore also be used particularly advantageously for batteries with direct cooling.

[0008] Preferably, the sealing elements are attached to the housing wall in the assembled state and spaced apart from the battery cells by a mounting gap. It is also possible and preferred for the sealing elements to be attached to the battery cells in the assembled state and spaced apart from the housing wall by a mounting gap. In particular, the sealing elements provide a mounting gap to the housing wall and / or to the battery cells in the assembled state. In the finished state, the mounting gap is closed, in particular, by the sealing element.

[0009] In the assembled state, the sealing elements are preferably spaced far enough from the housing wall and / or the battery cells to provide the clearance required for inserting the battery cells into the housing space. In particular, the assembly gap is dimensioned such that the battery cells can be inserted into the housing space (without placing undesirable stress on the sealing elements).

[0010] It is possible for the housing device to comprise at least one hollow profile element with at least one cavity. In particular, the cavity forms the housing space. In particular, the battery cells are inserted through an open end face of the hollow profile element. In particular, the sealing elements are spaced apart sufficiently in the assembled state that the battery cells can be inserted into the hollow profile element through the open end face. In particular, the hollow profile element provides the housing wall.

[0011] In an advantageous development, at least one sealing element can be pressed sealingly against at least one of the battery cells and / or the housing wall by means of the pretensioning device. In particular, the sealing elements, in the finished state, bear sealingly against the housing wall and / or the battery cells. In particular, the sealing elements, in the finished state, seal an area between the housing wall and at least one of the battery cells.

[0012] It is possible and advantageous for the pretensioning device to comprise spring elements. In particular, at least one spring element can be coupled to at least one sealing element, such that the spring element can press the sealing element against at least one of the battery cells and / or against the housing wall. It is possible for the sealing element to be spread open, at least in sections, by means of the spring element. The spring element is, in particular, a separate component. The spring element can also be at least partially integrated into the sealing element. In particular, the spring element can be or is fastened to the sealing element. In particular, the spring element provides the spring force for the required compression of the sealing element. In particular, the spring element is elastically deformable.

[0013] It is possible for the spring element to be arranged between at least two sealing lips of the sealing element. In particular, the spring element pushes the sealing lips apart. In particular, the sealing elements each comprise at least two sealing lips. In particular, in the finished state, at least one of the sealing lips rests against the battery cell and at least one other of the sealing lips rests against the housing wall.

[0014] It is possible for the spring element to be arranged at least partially within the cavity of a tubular sealing element. In particular, the spring element is designed such that it can spread the tubular sealing element. In particular, the sealing element is tubular. The sealing element can be annularly closed. In particular, the spring element is at least partially enclosed by the sealing element. In particular, the sealing element is arranged at least partially within the sealing element. It is also possible for the sealing element to be arranged at least partially outside the sealing element.

[0015] In an advantageous development, the spring element comprises at least one compression spring and in particular at least one metallic compression spring, or is designed as such. For example, a shaped spring steel can be provided. Other elastic materials are also possible. The spring element can also comprise at least one elastomer spring and / or at least one gas pressure spring, or be designed as such. The elastomer spring can be designed as a tube or a spiral. The gas pressure spring, in particular, comprises at least one pressurized internal volume. The internal volume can be delimited in a pressure-tight manner by the spring element and / or by the sealing element.

[0016] In an advantageous development, the sealing element is designed such that it is pressed at least partially against the battery cell and / or the housing wall by the pressure prevailing in the housing space (preferably by the coolant pressure). For example, at least one sealing flank is shaped such that the coolant pressure prevailing in the housing space presses the sealing flank against the battery cell and / or the housing wall. It is possible to provide at least two such sealing flanks, so that at least one sealing flank is available for each sealing surface (i.e., for the battery cell and the housing wall).

[0017] It is possible and advantageous for the prestressing device to be provided by at least one elastic (compressible) section of a respective sealing element. In particular, the sealing element is at least partially compressed in the assembled state. In particular, the elastic section is an integral component of the sealing element. For example, the section is designed as a tube or as a spiral or another compressible geometry. The section can also have a pressurized internal volume. In particular, the prestressing device is integrated into the material of the respective sealing element. In particular, the fixing device is suitable and designed to secure the sealing element in the compressed state.

[0018] In a preferred embodiment, the fixing device comprises fixing elements. Preferably, at least one fixing element secures at least one sealing element in the assembled state. In particular, each sealing element is equipped with at least one fixing element.

[0019] The fixing element is preferably coupled to the sealing element and / or to the pretensioning device in order to secure the sealing element in the assembled state. In particular, the fixing element is suitable and designed to secure the sealing element in the assembled state and simultaneously hold the pretensioning device in the pretensioned state.

[0020] It is possible and advantageous for the fixing element to engage around the sealing element and / or the pretensioning device, at least in sections, in a clamp-like manner. In particular, the fixing element is designed as a clamp or comprises at least one such clamp. In particular, the sealing element is secured in the assembled state by the clamp-like engagement. In particular, the fixing element can be deactivated by at least partially detaching it from the sealing element and / or from the pretensioning device. In particular, the sealing element enters the finished state by detaching the fixing element. In particular, the pretensioning device is also discharged in the process. Deactivation is understood to mean, in particular, the removal of the securing device in the assembled state to bring about the finished state.

[0021] In an advantageous development, the fixing element comprises at least one locking means (so-called locking connection). In particular, the fixing element can be deactivated by releasing the locking means. Preferably, the locking means is attached to the pretensioning device. It is possible for the locking means to be an integral component of the pretensioning device. However, it is also possible for the locking means to be attached to the sealing element. In particular, the locking means provides a force-fitting and / or positive-fitting connection when it is activated (locked).

[0022] The fixing element preferably has at least one gripping section. In particular, the gripping section serves for manual actuation and preferably for releasing the fixing element from the sealing element and / or from the pretensioning device. In particular, the gripping section is an integral component of the fixing element.

[0023] In an advantageous embodiment, the fixing element comprises at least one adhesive section. The adhesive section preferably fixes the sealing element and / or the pretensioning device by adhesive action such that the sealing element is secured in the assembled state. In particular, the fixing element can be deactivated by at least partially loosening or dissolving the adhesive section.

[0024] The adhesive section can be provided by an adhesive layer on the spring element and / or by a (dual-acting) adhesive tape. The adhesive section is released, in particular, by removing (tearing off) the adhesive section. It is also possible for the adhesive section to be released or detached by applying heat and / or a solvent. The adhesive section can also be provided by an adhesive applied directly to the sealing element.

[0025] It is preferred and advantageous that at least one holding device is assigned to each sealing element. In particular, the holding devices are suitable and designed to hold the sealing elements in their intended assembly position during targeted action on the fixing device. In particular, the holding device is supported on the sealing element and / or on the housing device and / or on the battery cell. In particular, at least one holding device is assigned to each fixing element. The holding device holds the sealing element, in particular, in the assembly position when the fixing device and in particular the fixing element is released from the sealing element.

[0026] In all embodiments, it is particularly preferred and advantageous for the sealing elements, in the finished state, to each annularly enclose at least one housing venting opening and at least one cell venting opening. In particular, this seals the corresponding venting connection from the housing space. In particular, the venting connection is delimited by the battery cell and the housing wall, and the at least one sealing element.

[0027] It is possible for at least one sealing element and the associated pre-tensioning device and the associated fixing device to be pre-assembled to form a sealing unit. In the pre-assembled state, the pre-tensioning device is, in particular, pre-tensioned. In the pre-assembled state, the sealing element is, in particular, in the assembled state. This enables particularly quick and uncomplicated installation of the sealing device.

[0028] The housing device is, in particular, a battery module housing. The battery device can comprise a plurality of battery module housings, each with a plurality of battery cells. In particular, a coolant can flow directly around the battery cells at least in sections. In particular, the housing space provides part of a coolant circuit. In particular, the sealing device seals the degassing connection with respect to the internal pressure or coolant pressure expected during operation in the housing space and / or the pressure expected in the degassing connection during a thermal event.

[0029] In particular, the sealing elements are suitable and designed to seal the housing space against the venting connections in a coolant-tight manner when finished. This ensures rapid and reliable venting even with direct cooling if a thermal event occurs. In the event of a thermal event, the gases can escape from the battery cells, particularly through the cell venting openings, into the venting connections and from there exit the housing device through the housing venting openings.

[0030] Further advantages and features of the present invention will become apparent from the embodiments which are explained below with reference to the accompanying figures.

[0031] The figures show: Fig. 1 a purely schematic representation of a battery device according to the invention in a sectional view with a sealing device in a finished state; Fig. 2 the battery device of the Fig. 1 with the sealing device in an assembled state; and Fig. 3-13 purely schematic detailed representations of sealing devices of a battery device according to the invention in cross-sectional views.

[0032] The Fig. Figure 1 shows a battery device 1 according to the invention with a housing device 2, which is designed here as a battery module housing for a battery module. The battery device 1 can comprise additional battery modules (not shown here), which can be interconnected, for example, to provide a high-voltage battery for driving an at least partially electrically powered motor vehicle.

[0033] A plurality of battery cells 3 are housed in the housing space 12 of the housing device 2, which are designed here, for example, as "prismatic" type Li-ion battery cells. The housing device 2 is designed here as a hollow profile element, the cavity of which provides the housing space 12. The housing space 12 is part of a coolant circuit, so that a cooling medium can flow directly around the battery cells 3.

[0034] The battery cells 3 each have a cell vent 13 (so-called cell vent) for discharging gases in the event of a thermal event. Housing vents 32 are formed in the housing wall 22, located at the bottom here, so that the gases can escape through them. The housing vents 32 are arranged opposite each cell vent 13. The housing vents 32 can be closed during normal operation and only open in the event of a thermal runaway.

[0035] In order to seal the housing space 12 against the cell vent openings 13 and the housing vent openings 32 in a coolant-tight manner, a sealing device 40 is provided. The sealing device 40 defines vent connections 23, each of which extends between a cell vent opening 13 and its corresponding housing vent opening 32. Because the vent connections 23 remain free, the fastest and safest possible venting is possible in the event of a malfunction, despite the direct cooling.

[0036] The degassing connections 23 are each surrounded and sealed in a ring-shaped manner by a sealing element 4 of the sealing device 40. The sealing element 4 lies sealingly against both the battery cell 3 and the housing wall 22 when it is in a finished state 24 (as shown here). Due to the V-shaped cross-section of the sealing element 4 shown here, the sealing flanks are pressed against the housing wall 22 and the battery cell 3 by the pressure of the coolant.

[0037] It has been shown that attaching the sealing elements 4 after inserting the battery cells 3 into the housing space 12 entails a very high installation effort. It has proven easier to mount the sealing elements 4 on the battery cells 3 or on the housing wall 22 and then insert the battery cells 3 into the housing space 12. To prevent damage to the sealing elements 4 during insertion, they must be maintained at a defined distance from their surroundings.

[0038] In the Fig. 2, the sealing elements 4 are shown in an assembled state 14. This creates a defined assembly gap 44 between the sealing elements 4 and the battery cells 3, allowing the battery cells 3 to be easily inserted into the housing space 12. The sealing elements 4 are each equipped with a pre-tensioning device 5 and a fixing device 6. By releasing the pre-tensioned pre-tensioning device 5, the sealing elements 4 are automatically transferred from the assembled state 14 to the finished state 24.

[0039] The sealing elements 4 are secured in the assembled state by means of the fixing device 6. Furthermore, the pre-tensioning device is thereby fixed in the pre-tensioned state. By selectively acting on the fixing device 6, the pre-tensioning device 5 is unloaded, and the sealing elements 4 are transferred to the finished state 24. To facilitate manual removal of the fixing elements 16, they are equipped with a gripping section 36.

[0040] In the example shown here, the pretensioning device is designed as a spring element 15, for example, as a shaped spring steel. The sealing element 4 is designed here, for example, in a ring shape and can be equipped with an annular spring element 15 or with two or more individual spring elements 15.

[0041] The fixing device 6 is designed here as a clamp-like fixing element 16, which grips the compressed sealing element 4 in a clamp-like manner. For example, the sealing element 4, which is designed in a ring shape here, can be fixed with two or more clamp-like spring elements 15. However, it is also possible to use a ring-shaped fixing element 16.

[0042] In the assembled state 14, the sealing element 4 is correspondingly flat, resulting in a sufficient assembly gap 44 for inserting the battery cells 3. For example, the sealing elements 4 are positioned together with the spring elements 15 and the fixing elements 16 on the battery cells 3 in the area of ​​the cell vent openings 13 and inserted together with them. Alternatively, the sealing elements 4, together with the spring elements 15 and the fixing elements 16, can also be pre-positioned on the housing wall 22.

[0043] Once the battery cells 3 are inserted into their final position, the fixing device 6 is acted upon from the outside through the housing venting opening 32, and the fixing elements 16, for example, are removed. As a result, the prestressed prestressing device 5 relaxes and presses the sealing element 4 against the sealing surfaces of the battery cell 3 and the housing wall 22, thus sealing the venting connection 23.

[0044] The Fig. 3 shows a cross-sectional detail of a sealing element 4 in the finished state 24. The spring element 15 is designed here as a metallic compression spring 25. The Fig. 4 shows the sealing element 4 of the Fig. 3 in the assembled state 14. For securing in the assembled state 14, a clamp-like fixing element 16 is provided, which engages around the sealing element 4 in the compressed state. The fixing element 16 is equipped with a gripping portion 36 to facilitate manual removal of the fixing element 16.

[0045] The Fig. 5 shows the sealing element 4 of the Fig. 4 with an alternative fixing element 16. The clamp-like fixing element 16 does not engage around the sealing element 4 here, but rather the pre-tensioned spring element 15. For this purpose, the spring element 15 protrudes from the sealing element 4 here.

[0046] In the Fig. 6 is the sealing element 4 of the Fig. 4 with an alternative design of the fixing element 16. The fixing element 16 is also designed like a clamp, but surrounds the sealing element 4 on an opposite side. The sealing element 4 is equipped with a holding device 7. This holds the sealing element 4 in its intended mounting position when the fixing element 6 is removed.

[0047] In the Fig. 7, the sealing element 4 is secured in the assembled state 14 by a fixing element 16 with an adhesive portion 46. For this purpose, the fixing element 16 can be provided with an adhesive layer or be designed as an adhesive tape. The fixing element 16 can also be provided by an adhesive layer applied directly to the sealing element 4. After the battery cells 3 have been inserted, the fixing element 16 is then detached from the sealing element 4. This can be done by removing or tearing it off, or by applying heat or using a solvent.

[0048] The Fig. 8 and Fig. 9 show an embodiment in which the fixing element 16 is designed as a locking means 26. The locking means 26 is formed integrally with the spring element 15. For example, the locking means 26 is provided by a correspondingly bent section of a spring steel. Fig. 8, the locking means 26 is shown in the released state. Fig. Figure 9 shows the locking means 26 in the locked (secured) state. By selectively deforming the locking means 26, the locking is released, and the sealing element 4 transitions to the finished state 24.

[0049] In the Fig. 10 and Fig. 11 shows a tubular sealing element 4. Inside the sealing element 4 there is at least one spring element 15. By compressing the sealing element 4, it is brought into the assembled state 14 and the spring element 15 is pre-tensioned. The securing in the assembled state 14 is carried out in a similar way to that described with reference to the Fig. 6 described by means of a clamp-like fixing element 16.

[0050] In the Fig. 12 and Fig. 13 shows a sealing element 4, which here is equipped with a spring element 15 designed as an elastomer spring 35. Securing in the assembled state 14 is achieved here with a clamp-like fixing element 16. In an alternative embodiment, the elastomer spring 35 can also be provided by an elastic and compressible portion of the sealing element 4. For example, the sealing element 4 is made entirely or partially of an elastic material. List of reference symbols: 1 battery device 2 Housing equipment 3 battery cells 4 Sealing element 5 Pre-tensioning device 6 Fixing device 7 Holding device 12 Housing space 13 Cell degassing opening 14 Assembly status 15 Spring element 16 Fixing element 22 Housing wall 23 Degassing connection 24 Finished state 25 compression spring 26 locking devices 32 Housing vent opening 35 elastomer spring 36 gripping section 40 Sealing device 44 Mounting gap 46 Adhesive section

Claims

[1] Battery device (1) for an at least partially electrically operated motor vehicle, comprising battery cells (3) each having at least one cell venting opening (13) for discharging gases in the event of thermal runaway of the battery cell (3), and comprising at least one housing device (2) having at least one housing wall (22) defining a housing space (12), wherein the housing wall (22) has housing venting openings (32) which are each arranged at least partially opposite to at least one of the cell venting openings (13), wherein a sealing device (40) with sealing elements (4) is arranged between the battery cells (3) and the housing wall (22), wherein the sealing elements (4) each seal at least one housing venting opening (32) with the at least one opposite cell venting opening (13) towards the housing space (12),so that sealed degassing connections (23) are created relative to the housing space (12), , characterized by that the sealing elements (4) can be transferred from an assembled state (14) into a finished state (24) in which they provide their sealing effect by relaxing a prestressed prestressing device (5), and that the sealing elements (4) can be secured in the assembled state (14) by means of a fixing device (6), and that by targeted action on the fixing device (6), the prestressing device (5) can be at least partially relaxed and the sealing elements (4) can be transferred into the finished state (24). [2] Battery device (1) according to the preceding claim, wherein the sealing elements (4) in the assembled state (14) are fastened to the housing wall (22) and spaced from the battery cells (3) or wherein the sealing elements (4) in the assembled state (14) are fastened to the battery cells (3) and spaced from the housing wall (22). [3] Battery device (1) according to one of the preceding claims, wherein the sealing elements (4) in the assembled state (14) are spaced apart from the housing wall (22) and / or from the battery cells (3) to such an extent that a distance required for inserting the battery cells (3) into the housing space (12) is provided. [4] Battery device (1) according to one of the preceding claims, wherein at least one sealing element (4) can be pressed sealingly onto at least one of the battery cells (3) and / or onto the housing wall (22) by means of the pretensioning device (5). [5] Battery device (1) according to one of the preceding claims, wherein the pretensioning device (5) comprises spring elements (15) and wherein at least one spring element (15) can be coupled to at least one sealing element (4) so ​​that the spring element (15) can press the sealing element (4) against at least one of the battery cells (3) and / or against the housing wall (22). [6] Battery device (1) according to the preceding claim, wherein the spring element (15) comprises at least one compression spring (25) and in particular at least one metallic compression spring and / or at least one elastomer spring (35) and / or at least one gas pressure spring. [7] Battery device (1) according to one of the two preceding claims, wherein the pretensioning device (5) is provided by at least one elastic portion of a respective sealing element (4) and wherein the sealing element (4) is at least partially compressed in the assembled state (14). [8] Battery device (1) according to one of the preceding claims, wherein the fixing device (6) comprises fixing elements (16) and wherein at least one fixing element (16) secures at least one sealing element (4) in the assembled state (14). [9] Battery device (1) according to the preceding claim, wherein the fixing element (16) is coupled to the sealing element (4) and / or to the pretensioning device (5) in order to secure the sealing element (4) in the assembled state (14). [10] Battery device (1) according to one of the two preceding claims, wherein the fixing element (16) encompasses the sealing element (4) and / or the pretensioning device (5) at least in sections in a clamp-like manner. [11] Battery device (1) according to one of the three preceding claims, wherein the fixing element (16) comprises at least one locking means (26) and wherein the fixing element (16) can be deactivated by releasing the locking means (26) and wherein the locking means (26) is preferably fastened to the pretensioning device. [12] Battery device (1) according to one of the four preceding claims, wherein the fixing element (16) comprises at least one gripping portion (36) for manual actuation and preferably for release from the sealing element and / or from the pretensioning device. [13] Battery device (1) according to one of the five preceding claims, wherein the fixing element (16) comprises at least one adhesive section (46) and wherein the adhesive section (46) fixes the sealing element (4) and / or the pretensioning device (5) by adhesive action such that the sealing element (4) is secured in the assembled state (14) and wherein the fixing element (16) can be deactivated by at least partially detaching the adhesive section (46). [14] Battery device (1) according to one of the preceding claims, wherein at least one holding device (7) is assigned to each of the sealing elements (4), and wherein the holding devices (7) are suitable and designed to hold the sealing elements (4) in their intended mounting position during the targeted action on the fixing device (6). [15] Battery device (1) according to one of the preceding claims, wherein the sealing elements (4) in the finished state (24) each surround at least one housing degassing opening (32) and at least one cell degassing opening (23) in an annular manner and thereby seal the corresponding degassing connection (23) towards the housing space.

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