CN113363647A

CN113363647A - Battery device and motor vehicle with battery device

Info

Publication number: CN113363647A
Application number: CN202110233027.5A
Authority: CN
Inventors: L·克鲁泽
Original assignee: Audi AG
Current assignee: Audi AG
Priority date: 2020-03-05
Filing date: 2021-03-03
Publication date: 2021-09-07
Anticipated expiration: 2041-03-03
Also published as: CN113363647B; DE102020105893A1

Abstract

The invention relates to a battery device (10) comprising a housing (20) and a plurality of battery elements (30) which are arranged next to one another in a receiving space (V) formed by the housing (20), wherein the battery device (10) further comprises at least one separating unit (40) for the battery elements (30), wherein in the receiving space (V) one separating unit (40) is arranged between two adjacent battery elements (30), wherein the respective separating unit (40) is mounted so as to be movable in a predetermined direction of movement (B) within a predetermined distance range (D) relative to the housing (20).

Description

Battery device and motor vehicle with battery device

Technical Field

The invention relates to a battery device comprising a housing and a plurality of battery elements arranged alongside one another in an accommodation space/volume formed by the housing. The battery device also has at least one separating unit for the battery elements, wherein one separating unit is arranged in each case in the receiving space between two adjacent battery elements. The invention also relates to a motor vehicle having a corresponding battery device.

Background

Such a battery device can be designed, for example, as a drive battery for a motor vehicle or aircraft. The battery device can thus be designed, for example, as a high-voltage battery or as a battery module of a high-voltage battery. "high voltage" in the sense of the present invention means in particular an operating voltage of about 30V to about 1kV in the case of alternating voltages or about 60V to about 1.5kV in the case of direct voltages. In order to provide electrical energy, i.e., for example, to drive a motor vehicle, the battery device usually has a plurality of battery elements, i.e., two or more battery elements. Accordingly, the battery element can be designed, for example, as a single battery module comprising a plurality of battery cells or as a single battery cell. In order to form a battery device, the battery elements are arranged in a known manner in a housing and are connected, for example, in series or in parallel with one another. As already mentioned, these battery elements are arranged alongside one another, i.e. stacked, in the housing receiving space and thus form a so-called cell group (Zellstapel).

The separation unit is generally mounted or arranged between the battery elements. As described in DE 102018204420 a1, such a separating unit can be designed, for example, as a shear wall. Such a shear wall can be used in particular for structural reinforcement of the battery device or, for example, as a protective wall, for example as a fire wall.

However, such a separate unit may also be used to reduce or slow down the aging rate of the battery element or battery device. That is, the battery element is generally unstable in shape. That is, each of the battery elements may be deformed due to an internal force occurring particularly during charging or discharging. Thereby generating a variation in the accommodation space of the battery element. This process is also known as "dilation" or "breathing". In order to prevent the cell elements from being pressed or displaced relative to one another when inflated, the cell elements can, for example, be fixed in a housing and separated from one another by means of the separating unit. However, by fixing between the cell elements or when using rigid and inflexible separating units, in particular during expansion or suction, clamping or pressing in of the respective cell elements can result. Thereby, the aging speed of the corresponding battery element is accelerated. In order to extend the service life of the battery device, methods for realizing elastic or flexible separating units between the battery elements are known from the prior art.

For example, DE 102016201604 a1 discloses that battery cells are each arranged between two fixed or rigid separating walls of a battery module, wherein a flexibly deformable first compensating element is arranged between a first battery cell and a separating wall adjacent to the first battery cell, and a flexibly deformable second compensating element is arranged between a second battery cell and a separating wall adjacent to the second battery cell. Here, the first compensation element and the second compensation element have different values of the deformation constant.

In this case, however, the deformation edges of the balancing elements must be determined accurately beforehand in order to be able to slow down the aging process of the cell element or the cell arrangement.

Furthermore, document WO 2017/055161 a1 discloses a battery module having a housing and electrochemical cells which are arranged side by side in the housing in a stacked manner. Here, the elastic element is arranged between two adjacent individual bodies. These resilient elements provide a predetermined compressive force to each of the battery cells when the cells expand, for example, during a charging or discharging process.

However, this can lead to uncontrolled displacement of the cells or the separating unit, so that, for example, individual battery cells in the housing are pressed or compressed.

Disclosure of Invention

It is an object of the present invention to provide a battery device that achieves swelling or breathing of the individual battery elements while avoiding compression or crushing of one battery element by other battery elements.

This object is achieved by the subject matter of the independent claims. Advantageous developments of the invention are disclosed by the dependent claims, the following description and the drawings.

The invention is based on the recognition that the above-mentioned object can be achieved by means of a dynamic one-piece auxiliary device, namely a separating unit, which is designed to be movable relative to the housing.

The invention therefore relates to a battery device of the type mentioned, which has a housing and a plurality of battery elements, i.e. two or more battery elements. The battery elements are arranged side by side or stacked in the receiving space formed by the housing. The battery elements form a so-called cell stack in a known manner. Additionally, the battery device has at least one separating unit for the battery elements. In this case, the separating unit is always arranged between two adjacent battery elements in the receiving space. Thus, the battery elements and the separation units are alternately arranged side by side in the housing. Thus, the monomer set also includes a separation unit. In order to achieve expansion without affecting the service life of the battery device or of the individual battery elements, the respective separating unit is mounted so as to be movable relative to the housing in a predetermined direction of movement within a predetermined distance range. How to determine the distance range and the movement direction will be described in detail again below.

In other words, the separating unit can thus be moved relative to the housing when the battery element breathes. The movement or movement is carried out only in the direction of movement and is limited by a predetermined or predetermined distance range. The distance ranges thus form a maximum movement pitch or a maximum movement distance of the respective separating unit relative to the housing.

This results in the advantage that, by means of the separating unit, in particular during the contraction or exhalation of the battery elements, a maximum distance between the battery elements is predefined. However, uncontrolled movements and thus the pressing or compression of one cell by the other cell can also be avoided at the same time as the cell expands or sucks air. It is thus possible to compensate for forces and tolerances between the battery elements during the service life of the battery device and thus to achieve a uniform ageing of the battery elements. Furthermore, the geometric orientation of the battery element in the housing receiving space can also be simplified by means of the separating unit.

The predetermined moving direction is preferably a direction in the stacking direction or the arrangement direction, i.e., parallel to the stacking direction of the battery elements. In other words, the respective separating unit can be moved with the respective broad side, i.e. with the contact surface facing the respective cell element, towards the respective broad side or contact surface of the respective cell element or away from the respective cell element. The direction of movement therefore preferably describes the movement or movement of the separating unit between two adjacent battery elements. Here, the broad side refers to the face of the geometry having the largest surface. In contrast, for example, the respective narrow side is a side of the geometric shape that is narrower than the wide side. The narrow sides are in particular perpendicular to the respective wide sides, and therefore two opposite wide sides are connected to one another. A rectangular or cuboid object accordingly has, for example, two opposite broad sides oriented parallel to one another and four narrow sides, which connect the two broad sides to one another, and which are formed perpendicularly to the broad sides.

The invention also includes embodiments that yield additional advantages.

Now, an advantageous embodiment of the separating unit for displacing the separating unit relative to the housing is first of all realized below.

According to one embodiment, the respective separating unit has at least one guide element on each of the two opposite narrow sides in order to mount the respective separating unit in a movable manner relative to the housing. At the same time, the housing also has at least one recess on the respective wall surface facing the respective narrow side for receiving and guiding the guide element in a predetermined distance range in a predetermined direction of movement.

In other words, the respective guide element can therefore be inserted or inserted, preferably threaded, into a recess of the housing wall surface assigned to the guide element. The shape of the recess, in particular the edge of the recess, defines the distance range and the direction of movement. The maximum distance between two adjacent battery elements is therefore also defined by the shape of the recess.

The guide elements can be arranged, for example, as projections or bulges or pins on the respective narrow side of the separating unit. The recess can be configured accordingly as an opening, i.e. a cutout or a groove, in the respective wall of the housing.

The two wall surfaces comprising the respective recess are preferably two opposite sides or side walls of the housing. In this case, the side face refers to a wall of the housing, which in the intended installation position of the battery device is oriented perpendicular to the bottom face and/or the top face. The bottom surface and the top surface are also interconnected by respective side surfaces. The installation position is the position for a battery device, which is used as an electrical energy accumulator, for example as a drive battery of a motor vehicle, as intended. In the installed position, the bottom and top surfaces are preferably oriented parallel to a predetermined ground surface, for example a roadway ground surface. The narrow side of the separating unit, which comprises the respective guide element, can therefore also be referred to as the lateral narrow side.

In order to be able to ensure a regular movement of the respective separating unit and to avoid jamming of the separating unit in the housing, the respective separating unit preferably has two or more guide elements on each narrow side according to a further embodiment. That is, the respective separation unit comprises two or more guide elements on two opposite narrow sides, respectively. The guide elements of each narrow side are arranged offset from one another along the respective narrow side perpendicular to the predetermined direction of movement. The guide elements thus have a predetermined distance from one another. Accordingly, the housing also has two or more recesses on the respective wall surface facing the respective narrow side for receiving and guiding the respective guide element in the predetermined movement direction within a predetermined distance range. The number of recesses per wall surface preferably corresponds here to the number of guide elements. Thus, one recess is assigned to each guide element.

In order to specify the predetermined direction of movement, it is proposed according to a further embodiment that the respective guide element bears against a first edge and an opposite second edge of the recess perpendicularly to the predetermined direction of movement. Thus, the opposite edges of the recess define a movement gap of the respective guide element perpendicular to the predetermined movement direction.

In other words, the shape of the respective guide element perpendicular to the predetermined direction of movement is matched to the shape of the respective associated recess. However, in the direction of the predetermined direction of movement, the shape of the recess has a larger dimension than the shape of the corresponding guide element.

In order to ensure or ensure the stability of the housing even when the recesses are introduced into the corresponding wall surface, it is preferably provided that the guide elements of two adjacent separating units and the corresponding recesses are arranged offset to one another. In other words, the guide elements of two adjacent separating units associated with the respective narrow side and the corresponding recesses of the respective wall surface are arranged offset from one another perpendicular to the predetermined direction of movement.

The recesses of the respective wall surfaces thus have a predetermined spacing relative to one another in the direction of movement. In this case, each two recesses are formed parallel to the direction of movement, i.e. at a height in the direction of movement, and two adjacent recesses are always formed offset from one another perpendicular to the direction of movement. Similarly, this naturally also applies to the corresponding guide element. The predetermined distance is preferably defined by the dimensions and the expansion behavior of the respective battery element, i.e. by the expansion of the respective battery element during respiration.

The dimensions of the distance range are advantageously realized in the following embodiments. The distance range is therefore 10%, in particular 5%, of the width or thickness of the respective cell element. Here, the width or thickness of the battery element in the normal state is meant, that is to say, for example, immediately after the production is completed, before respiration or swelling occurs. The distance range thus describes how far the guide element can be moved back and forth in the direction of movement in the recess, i.e. between the two stop edges, i.e. between the above-mentioned first and second edges of the recess.

In order to hold, i.e. to fix or position, the battery element against slipping out of the receiving space, according to a further embodiment the respective separating unit has at least one holding element/restraint element. Preferably, the holding element is arranged or fixed on a narrow side of the respective separation unit, which narrow side connects two opposite or lateral narrow sides comprising the guide element. The narrow side may preferably face the top surface of the housing in the aforementioned mounting position. Thus, the narrow side may also be referred to as the upper narrow side.

The holding element can be designed in particular as a spring element or as a spring clip. Preferably, each holding element holds two adjacent battery elements here. That is to say, the holding element extends beyond the upper narrow side in the direction of movement.

In order to ensure the stability of the separating unit, according to a further embodiment, the respective separating unit has an inherently rigid or dimensionally stable frame. The elastic element of the separating unit is held in the frame. Thus, the frame maintains the shape of the elastic element. The expansion or deformation of the respective spring element can therefore be caused by the expansion process during respiration of the respective battery element.

The advantage obtained by this design of the separating unit is that the respective separating unit is held stable by the frame on the one hand, but on the other hand, the respective battery element is also provided with additional play for breathing by the elastic element.

The respective guide element is preferably formed integrally with the frame. That is, the respective guide element is an integral part of the frame. Similarly, this preferably also applies to the corresponding retaining element.

In this context, according to a further embodiment, it is provided that the frame is at least partially, i.e. partially or completely, formed so as to overlap the side of the battery element facing the separating unit. In other words, the frame may partially protrude from the corresponding side or wide side of the corresponding battery element in a state of being disposed in the housing receiving space. Preferably, however, the frame is closed off in a planar manner with the respective side of the respective cell element.

Therefore, a certain stability between the battery elements can be ensured by the frame.

The invention also relates to a motor vehicle having a battery device as described above. The motor vehicle is preferably designed as a motor vehicle, in particular as a passenger vehicle or a truck, or as a passenger vehicle or a motorcycle. In particular, the motor vehicle is designed as an electric vehicle or a hybrid vehicle. In this case, the battery device can be designed as a drive battery of a motor vehicle.

The invention also comprises a combination of features of the described embodiments.

Drawings

Embodiments of the present invention are described below. For this purpose, it is shown that:

fig. 1 shows a schematic illustration of an exemplary embodiment of a battery device, in which a separating unit is arranged as a device aid between the battery elements;

FIG. 2 shows a schematic diagram of an enlarged view of a battery device; and

fig. 3 shows a schematic illustration of an exemplary embodiment of a separation unit.

Detailed Description

The examples set forth below are preferred embodiments of the invention. In the exemplary embodiments, the described parts of the embodiments are in each case individual features of the invention which can be considered independently of one another and which in each case also improve the invention independently of one another. Thus, the disclosure also includes different combinations of features from the illustrated combinations of embodiments. Furthermore, the embodiments can also be supplemented by further features of the invention already described.

In the drawings, like reference numbers indicate functionally similar elements, respectively.

Fig. 1 shows a schematic three-dimensional view of a battery device 10 from a perspective view. The battery device 10 is configured as a battery module. In order to provide electrical energy, the battery device 10 therefore comprises a plurality of battery elements 30 which are arranged stacked side by side in a receiving space V formed by the housing 20 of the battery device 10 and are electrically connected to one another in a known manner. The battery elements 30, which are currently embodied as battery cells, thus form a cell stack in a known manner. For a better overview, only two such battery elements 30 are shown in fig. 1 in the housing 20.

Fig. 1 shows the battery device 10 in the mounted position as described above. The housing 20 here comprises four side faces or walls 21 which define the receiving space V in the x-direction and the y-direction. The bottom surface of the housing 20 is formed here by flanges or projections of two opposite side surfaces 21 of the housing 20. These two opposite side faces 21, also referred to below as side plates 23, are oriented in the x direction and are therefore arranged parallel to the stacking direction R of the battery elements 30 as cell groups. Therefore, the stacking direction corresponds to the x direction. The other two opposite side faces 21 connecting the side plates 23 to one another are correspondingly oriented perpendicularly to the stacking direction R. These sides are also referred to below as closing plates 22. For a better overview, the top side of the housing 20 is not shown in fig. 1. The bottom and top surfaces define a receiving space V in the z direction.

In order to enable the battery elements 30 to breathe or expand in the housing 20 and at the same time avoid a compression or pressing of the battery elements 30 against one another as a result thereof, a separating unit 40 is provided between two adjacent battery elements 30, respectively. Therefore, the cell group always alternately includes the battery element 30 and the separation unit 40. In this case, the individual battery elements 30 are always oriented with their respective wide side 31 toward the respective wide side 46 of the separating unit 40.

The respective separating unit 40 is mounted in the housing 20 so as to be movable in a predetermined direction of movement B within a predetermined distance range D relative to the housing 20. That is, when the battery breathes or swells, the corresponding separation unit 40 can reciprocate relative to the housing in the predetermined moving direction B between two adjacent battery elements 30. The amount by which the respective separating unit 40 can be moved is limited here by the distance range. The maximum distance between the battery elements 30, which is defined by the separating unit, can thus be maintained, in particular when the battery elements 30 contract or exhale. This also results in the advantage that the corresponding separating unit 40 also simplifies the geometric arrangement of the battery elements 30 as a cell stack in the receiving space V. Thus, the separation unit 40 may also be referred to as a monomer assist device.

The movable mounting of the respective separating unit 40 relative to the housing 20 is achieved here by two different measures. The first measure is here the so-called guide elements 42, which are arranged on two opposite narrow sides 41 of the separating unit 40. In order to avoid jamming of the separating units 40, the respective separating unit 40 currently has two such guide elements 42 on each narrow side 41. These guide elements are arranged at a defined distance from one another in the z direction, i.e. perpendicular to the direction of movement B, along the narrow side 41. As shown in fig. 1, the narrow sides 41 represent those sides of the respective separation units 40 that face the side plates 23 of the housing 20. Possible dimensions and configurations of these guide elements 42 and the separating unit are described in detail again later with reference to fig. 2 and 3.

As a second measure, each of the side plates 23 comprises a recess 24 corresponding to the respective guide element 42. Each guide element is provided with exactly one recess 24. Corresponding guide elements 42 can be guided or inserted through these recesses 24. That is, the respective recess 24 can always receive and guide the at least one guide element 42 within the predetermined distance range D along the predetermined direction of movement B.

To illustrate this, fig. 2 again shows an enlarged view of the battery device 10 according to fig. 1. As shown in fig. 2 (and also in fig. 3), the guide elements 42 are designed as pins. The guide elements 42 are arranged on the respective narrow side 41 in such a way that they have a greater extent in the direction of movement B than the respective narrow side 41 itself. That is, the guide elements project beyond the two opposite broad sides 46 of the separating unit 40 in both directions.

Accordingly, the recess is designed here as a pin-shaped or elongated slot. The dimensions of the recess 24 are matched to the dimensions of the guide element 42, at least perpendicularly to the direction of movement B. In other words, to determine the direction of movement B, the respective guide element rests on a first edge R1 and a second edge R2 opposite the first edge R1. This enables a movement of the separating unit 40 in the movement direction B and at the same time prevents a movement of the separating unit 40 perpendicular to the movement direction B, i.e. in the z direction. In contrast, in the direction of movement B, the recess has a larger dimension than the corresponding guide element 42. The difference in size between the respective guide element 41 and the corresponding recess 24 in the direction of movement B defines the distance range D.

In order to hold or fix the battery element 30 in the cell assembly arrangement, the respective separating unit 40 further comprises at least one holding element 43. As shown in fig. 1, two such retaining elements 43 are provided here. The holding element 43 is arranged on the narrow side 41 of the separating unit 40 facing the top face of the housing 20. The holding elements 43 are at a predetermined distance from one another along the narrow side 41, i.e. in the y direction. Thereby, the battery element 30 can be prevented from slipping out of the receiving space V perpendicularly to the direction of movement B, i.e. in the z-direction. Each holding element 43 holds two adjacent battery elements 30. The respective holding element 43 therefore projects here likewise in the x direction beyond the two opposite broad sides 46 of the separating unit 40. In the embodiment according to fig. 1 or 3, the holding elements 43 are embodied here as spring elements which exert a pressing force on the battery element 30 in the z direction, in particular in the direction toward the bottom.

Fig. 3 finally shows again an exemplary configuration of the separation unit. As shown in fig. 3, the separating unit 40 here comprises a frame 44. The frame 44 is designed to be inherently rigid or dimensionally stable. The guide element 42 and the holding element 43 are preferably formed integrally with the frame 44. The elastic member 45 of the separation unit 40 is held by the frame 44. The elastic element 45 is thus clamped in the frame 44. Accordingly, the frame 44 can ensure stability of the separation unit 40. On the other hand, the breathing of the battery element 30 can also be better achieved by the elastic element. Thus, the elastic element is unstable in shape and may be reversibly deformed or move together when the battery element breathes.

Thus, a single auxiliary device is realized by the separation unit 40 and the recess 24. That is, the battery element 30 or the battery cells may be spatially oriented in the housing 20. Since the cell support device is dynamic in this case, i.e. can be moved in the predetermined direction of movement B within the distance range D, the forces occurring during expansion can be compensated for over the service life of the battery device 10, and therefore a uniform aging of the battery cells or the battery elements 30 is achieved. Furthermore, the monomers can also be oriented autonomously along the direction of movement B. In summary, the exemplary embodiments show a modular, single-piece auxiliary device with force and tolerance compensation.

Claims

1. A battery device (10) comprising a housing (20) and a plurality of battery elements (30) which are arranged alongside one another in a receiving space (V) formed by the housing (20), the battery device (10) further comprising at least one separating unit (40) for the battery elements (30), wherein in the receiving space (V) one separating unit (40) is arranged between two adjacent battery elements (30) each,

it is characterized in that the preparation method is characterized in that,

the respective separating unit (40) is mounted so as to be movable in a predetermined direction of movement (B) within a predetermined distance range (D) relative to the housing (20).

2. Battery device (10) according to claim 1, characterized in that, for the movable support of the respective separating unit (40) relative to the housing (20), the respective separating unit (40) has at least one guide element (42) on two opposite narrow sides (41), respectively, and the housing (20) has at least one recess (24) on the respective wall surface (23) facing the respective narrow side (41) for receiving and guiding the guide element (42) in a predetermined distance range (D) in a predetermined direction of movement (B).

3. Battery device (10) according to one of the preceding claims, characterized in that, for the purpose of movably supporting the respective separating unit (40) relative to the housing (20), the respective separating unit (40) has on two opposite narrow sides (41) two or more guide elements (42) respectively, which are arranged offset along the respective narrow side (41) perpendicularly to the predetermined direction of movement (B), the housing (20) has on the respective wall surface (23) facing the respective narrow side (41) two or more recesses (24) for receiving and guiding the respective guide elements (42) within the predetermined distance range (D) in the predetermined direction of movement (B).

4. Battery device (10) according to claim 2 or 3, characterized in that, for defining the predetermined direction of movement (B), the respective guide element (42) bears against a first edge (R1) of the recess and a second edge (R2) opposite the first edge, perpendicular to the predetermined direction of movement (B).

5. Battery device (10) according to one of claims 2 to 4, characterised in that the guide elements (42) of two adjacent separating units (40) associated with the respective narrow side (41) and the recesses (24) of the respective wall surface (23) corresponding to the guide elements are arranged offset relative to one another perpendicularly to the predetermined direction of movement (B).

6. Battery device (10) according to one of the preceding claims, characterized in that the distance range (D) is 10%, in particular 5%, of the width of the respective battery element (30).

7. Battery device (10) according to one of the preceding claims, characterized in that, for retaining at least one battery element (30) in the receiving space (V), the respective separating unit (40) has at least one retaining element (43).

8. Battery device (10) according to one of the preceding claims, characterized in that the respective separating unit (40) has an inherently rigid frame (44) in which the elastic element (45) of the separating unit (40) is held, wherein the respective guide element (42) is formed integrally with the frame (44).

9. Battery device (10) according to claim 8, characterized in that the frame (44) is at least sectionally configured to overlap the side of the respective battery element (30) facing the respective separating unit (40).

10. A motor vehicle having a battery device (10) according to any one of the preceding claims.