BATTERY MODULE HOUSING FOR ONE BATTERY MODULE, BATTERY MODULE AND ELECTRICAL ENERGY STORAGE

Description

[0001] The invention relates to a battery module housing for a battery module of an electrical energy storage device with at least one battery cell according to the preamble of patent claim 1. Furthermore, the invention relates to a battery module and an electrical energy storage device.

[0002] Battery module housings are already known from the prior art and are designed for electrical energy storage, for example in motor vehicle construction. At least one battery cell, in particular a plurality of battery cells, can then be installed within the battery module housing, the battery module housing thus forming a frame for the battery cells. The battery cells can, for example, be pouch cells which undergo a volume change depending on a cell state, in particular depending on a current state of charge and depending on the age of the battery cell. This volume change is also referred to as cell respiration. It is important that the volume change of the battery cell can be compensated within the battery module housing.Furthermore, with prismatic cells, for example, it is necessary that a predetermined pressure value is exerted on the battery cells so that improved performance of the battery cells can be achieved.

[0003] According to DE 10 2018 204 220 A1, a battery is disclosed comprising at least one battery cell, each battery cell having a plurality of parallel-stacked electrodes and a pressure device by which the electrodes can be subjected to pressure. A frame is closed on all sides. The pressure device and the at least one battery cell are arranged within the frame in a longitudinal direction of the frame such that, when the pressure device exerts the pressure, a pressure region of the pressure device presses against the electrodes in the longitudinal direction, and a support region of the pressure device opposite the pressure region is supported by a first frame wall of the frame in a longitudinal direction opposite the longitudinal direction.

[0004] EP 3 189 552 A2 relates to a clamping device for battery cells, wherein a container comprising a space with a variable volume is designed to receive the fluid and wherein the container is designed such that one battery cell or a plurality of battery cells can be clamped.

[0005] DE 10 2019 007 748 A1 relates to an electrical energy storage device with at least one electrode stack, which comprises a plurality of layers of electrodes arranged one above the other in a stacking direction and separators arranged between the electrodes. At least one pressure plate is provided for exerting a pressure on the electrode stack acting counter to the stacking direction. At least one actuator is provided for applying a force to the pressure plate. The electrode stack and the pressure plate are arranged in a housing of the electrical energy storage device. The electrical energy storage device has a control device for controlling the at least one actuator. The control device is designed to apply a substantially constant force to the pressure plate by means of the actuator, depending on a respective thickness of the at least one electrode stack.

[0006] EP 3 886 202 A1 relates to a battery system comprising a stack with a plurality of battery cells, fluid springs, and fluid pressure adjustment means. The fluid springs are arranged between a first and a second end plate and are configured to exert a pressure on the battery cells. At least one of the fluid springs comprises an elastic device, wherein the elastic device has a predefined modulus of elasticity. The fluid pressure adjustment means is connected to one or more fluid springs comprising an elastic device configured to create a negative pressure in the fluid within the connected fluid springs. Furthermore, the battery system makes it possible to avoid or minimize the risk of thermal runaway spreading between different cells of the battery system.

[0007] The object of the present invention is to provide a battery module housing, a battery module and an electrical energy storage device by means of which an improved operation of a battery cell can be realized.

[0008] This object is achieved by a battery module housing, a battery module, and an electrical energy storage device according to the independent patent claims. Advantageous embodiments are specified in the subclaims.

[0009] A first independent aspect of the invention relates to a battery module housing for a battery module of an electrical energy storage device with at least one battery cell, wherein the at least one battery cell undergoes a volume change depending on a cell state, with at least one module frame which forms at least a first receiving area for the at least one battery cell and a second receiving area for a pressure regulating device of the battery module housing, wherein the pressure regulating device contacts at least partially the at least one battery cell in the assembled state of the battery module and is designed to set a predetermined pressure value on the battery cell depending on the volume change.

[0010] It is provided that the pressure regulating device has at least a first hose-like and flexible pressure body and a separate second hose-like and flexible pressure body, wherein a movable intermediate pressure plate is formed between the first pressure body and the second pressure body, which intermediate pressure plate contact the first pressure body and the second pressure body at least in some areas.

[0011] In particular, improved operation of the at least one battery cell can thus be achieved, since in particular a continuous and simpler structure of the pressure regulating device can be provided. In particular, on the basis of the tubular and flexible pressure bodies, reliable and constantly distributed pressure can be exerted on the at least one battery cell. The first pressure body and the second pressure body can thus realize small volume changes within the pressure bodies, wherein a corresponding pressure value can then nevertheless be reliably exerted on the basis of the at least two pressure bodies. The intermediate pressure plate is designed in particular to exert the pressure of the first pressure body constantly and evenly distributed on the second pressure body, wherein the second pressure body is contacted with the at least one battery cell, for example via a pressure plate.In particular, it can then be provided that in the presented embodiment, the first pressure body is supported, for example, on the module frame, whereby the corresponding pressure value can then be exerted on the at least one battery cell, which is supported on an opposite side of the module frame.

[0012] By using several pressure hulls or a large number of pressure hulls, a large volume compensation of the volume-variable cells can be achieved in an additional space-saving manner.

[0013] In this case, the movable intermediate pressure plate is to be understood in particular as meaning that it can change its position, in particular move, within the module frame depending on the change in volume or pressure regulation.

[0014] In particular, this allows the pressure body to be in full contact with the intermediate pressure plate and the pressure plate, thus enabling precise force determination on the respective plates via the tube pressure. No sensor is required for this, which leads to cost savings. Furthermore, no deflection of the pressure plate can be detected. Furthermore, a low pressure level can be achieved in the tube, compared to, for example, air bellows, at the same cell pressure. Furthermore, the block length is very short compared to an air bellows solution, thus saving installation space. Furthermore, a high degree of installation space flexibility is achieved, since the tube-like pressure bodies, in particular, can be better integrated into the square and usually flat installation space of the battery module housing or battery module than corresponding air bellows or cylinders.Furthermore, weight savings can be achieved because the corresponding tube-like pressure bodies are very thin and lightweight. The pressure plate or intermediate pressure plate can also be designed very slim and made of a thin material. This allows for a very homogeneous pressure distribution across the battery cell surface.

[0015] In particular, the invention thus solves the problem that the at least one battery cell, in particular a plurality of battery cells, must be clamped within the battery module, in this case within the battery module housing. The battery cells are in particular so-called pouch cells or prismatic cells, which, for example, have increased cell respiration, wherein cell respiration describes a change in volume or the state of charge. A system is therefore necessary which compensates for the change in volume. In addition, it can be provided that some battery cells require a so-called clamping force, i.e. a pressure orthogonal to the battery cell surface, in order to function accordingly. For example, such a clamping force is necessary in solid-state cells whose layers are pressed together using pressure in order to optimize surface contact and reduce cell resistance.Furthermore, for example, with so-called lithium metal anodes, which build up as a layer during the charging process and degrade during the discharging process, a corresponding clamping force may be necessary. In particular, this creates what is known as cellular respiration. Furthermore, such battery cells must be compressed to enable the deposition or deposition processes so that flat layers can build up and degrade. For this to happen, it is particularly important that the pressure on the battery cells must be maintained at all times, meaning that the pressure regulating element, which can also be referred to as a pressure application element, must be in contact with the cell at all times and transmit a force, despite changes in the battery cell's volume.

[0016] Furthermore, it is provided that the first pressure body and / or the second pressure body have reinforcements at respective edge regions and / or corner regions. For example, if the battery module housing is provided in a substantially cuboid shape, reinforcements can be provided at corresponding corners, thus ensuring a long service life of the first pressure body and the second pressure body.

[0017] Furthermore, the first pressure body and the second pressure body are formed from a rubber-like material. In particular, the first pressure body and the second pressure body can thus be provided in a type of bicycle tube. This makes it easy to regulate the pressure within the battery module housing. These materials are particularly lightweight and cost-effective, allowing the first pressure body and the second pressure body to be provided within the battery module housing with high flexibility.

[0018] It is also advantageous if at least the first pressure body and the second pressure body are fluidly connected to each other. Thus, only one pressure regulating device is required to adjust the pressure in both the first pressure body and the second pressure body. This saves installation space and components.

[0019] In a further advantageous embodiment, at least the first pressure body and the second pressure body are fluidically connected to one another via a fluidic connection which is guided through a recess within the intermediate pressure plate. This makes it possible to realize a fluidic connection between the first pressure body and the second pressure body in a space-saving manner. The recess can be provided, for example, in the form of a hole or a cylinder, in which case the first pressure body can then be connected or welded to the second pressure body via a likewise rubber-like or hose-like connection. This allows for simple yet reliable pressure regulation within the pressure regulation device.

[0020] It has also proven advantageous if a filling valve for fluidically filling the first pressure body and / or the second pressure body is formed on a module frame. In particular, the module frame has only a single filling valve, in which case the first pressure body and the second pressure body are also fluidically connected to each other. Thus, the first pressure body and / or the second pressure body can be fluidically filled outside the module frame.

[0021] Furthermore, it has proven advantageous if the shape of the first pressure body and / or the second pressure body, at least in some areas, essentially corresponds to the shape of the second receiving area. In particular, the flexible, particularly tubular and rubber-like, first pressure body and / or second pressure body can adapt to the shape of the receiving area. Furthermore, the first pressure body and the second pressure body can already have a substantially prefabricated shape, for example, a substantially cuboid shape, so that improved pressure distribution can be achieved by the first pressure body and / or the second pressure body.

[0022] It has also proven advantageous if a cross-section of the first pressure body and / or the second pressure body is substantially oval or substantially round. In particular, this allows for a simple manufacturing method for the first pressure body and the second pressure body. In particular, the first pressure body and / or the second pressure body are flexible enough that, after pressure is applied, the oval or round shape can adapt to the corresponding shape of the at least second receiving area. Thus, pressure regulation within the battery module housing can be achieved reliably and easily.

[0023] A further aspect of the invention relates to a battery module for an electrical energy storage device with at least one battery module housing according to the preceding aspect and with at least one battery cell, wherein the at least one battery cell undergoes a volume change depending on a cell state.

[0024] Yet another aspect of the invention relates to an electrical energy storage device, in particular for an at least partially electrically powered motor vehicle, having at least one battery module according to the preceding aspect. In particular, for example, the electrical energy storage device can also have a second battery module according to the preceding aspect. Furthermore, the electrical energy storage device can have further battery modules. Furthermore, the electrical energy storage device can, for example, have a corresponding management system to monitor pressure regulation and corresponding charge states of the battery module. The electrical energy storage device can, for example, be designed as a traction battery of an at least partially electrically powered motor vehicle.

[0025] Furthermore, yet another aspect of the invention relates to a motor vehicle with at least one electrical energy storage device according to the preceding aspect. The motor vehicle is designed, in particular, as an at least partially electrically powered motor vehicle, in particular as a fully electrically powered motor vehicle.

[0026] An independent second aspect of the invention relates to a battery module housing for a battery module of an electrical energy storage device with at least one battery cell, wherein the at least one battery cell undergoes a volume change depending on a cell state, with at least one module frame which forms at least a first receiving area for the at least one battery cell and a second receiving area for a pressure regulating device of the battery module housing, wherein the pressure regulating device contacts the at least one battery cell at least in some areas in the assembled state of the battery module and is designed to set a predetermined pressure value on the battery cell depending on the volume change.It is provided that the pressure regulating device has at least one first hose-like and flexible pressure body, wherein at least one pressure body is formed from a rubber-like material.

[0027] Furthermore, a third, yet independent aspect of the invention relates to a battery module housing for a battery module of an electrical energy storage device with at least one battery cell, wherein the at least one battery cell undergoes a volume change depending on a cell state, with at least one module frame which forms at least a first receiving area for the at least one battery cell and a second receiving area for a pressure regulating device of the battery module housing, wherein the pressure regulating device contacts the at least one battery cell at least in some areas in the assembled state of the battery module and is designed to set a predetermined pressure value on the battery cell depending on the volume change.It is provided that the pressure regulating device has at least one hose-like flexible pressure body, wherein at least one pressure body has a reinforcement at respective edge regions and / or corner regions.

[0028] Advantageous embodiments of the first aspect of the invention are to be regarded as advantageous embodiments of the battery module, as well as of the electrical energy storage device and of the motor vehicle. Furthermore, the advantageous embodiments of the first aspect of the invention are also to be regarded as advantageous embodiments of the two independent second and third aspects, i.e., the pressure regulating device with the hose-like, flexible pressure body, wherein the pressure body consists of a rubber-like material and / or wherein the pressure body has reinforcement at respective edge regions and / or corner regions. The features of the first independent aspect can be freely combined with the features of the second independent aspect and the third independent aspect.

[0029] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combinations, but also in other combinations or on their own, without departing from the scope of the invention.

[0030] Showing: Fig. 1 is a schematic side view of an embodiment of a motor vehicle with an embodiment of an electrical energy storage device; Fig. 2 is a schematic view of an embodiment of a battery module; Fig. 3 is a further schematic plan view of the battery module according to Fig. 2 ; Fig. 4 shows a schematic perspective view according to an embodiment of a pressure body of an embodiment of a battery module housing; and Fig. 5 shows a schematic perspective view of an embodiment of a battery module.

[0031] In the figures, identical or functionally identical elements are provided with the same reference numerals.

[0032] Fig. 1 shows a schematic side view of an embodiment of a motor vehicle 10 with an embodiment of an electrical energy storage device 12. The motor vehicle 10 can be designed, in particular, as an at least partially electrically operated motor vehicle, in particular as a fully electrically operated motor vehicle. The electrical energy storage device 12 can then be designed, for example, as a traction battery for driving an electric drive device of the at least partially electrically operated motor vehicle 10. Furthermore, the electrical energy storage device 12 can be designed to operate an on-board electrical system of the motor vehicle 10. In the present case, the electrical energy storage device 12 has, in particular, a first battery module 14 and a second battery module 16.

[0033] Fig. 2 shows a schematic plan view according to an embodiment of the battery modules 14, 16, wherein the corresponding features are described below only for the first battery module 14. However, the features are also transferable to the second battery module 16. In particular, the Fig. 2 the first battery module 14. The battery module 14 has at least one battery cell 18, in this case in particular four battery cells 18. The battery cells 18 are in particular so-called solid-state cells, which operate cellular respiration and thereby undergo a volume change depending on the aging state and the charge state of the battery cells 18. For this purpose, in order to be able to carry out cellular respiration, a pressure regulating device 20 is provided according to the invention. The pressure regulating device 20, in turn, is part of a battery module housing 22.

[0034] The battery module housing 22 is designed in particular for the electrical energy storage device 12, wherein at least one battery cell 18 undergoes a volume change depending on a respective cell state. For this purpose, the battery module housing 22 has, in particular, a module frame 24, which forms at least a first receiving area 26 for the at least one battery cell 18 and a second receiving area 28 for the pressure regulating device 20. The pressure regulating device 20 contacts at least one battery cell 18 in the assembled state of the battery module 14, at least in some areas, and is designed to set a predetermined pressure value on the battery cell 18 depending on the volume change.

[0035] It is provided that the pressure regulating device 20 has at least a first hose-like and flexible pressure body 30 and a separate second hose-like and flexible pressure body 32, wherein a movable intermediate pressure plate 34 is formed between the first pressure body 30 and the second pressure body 32, which the first pressure body 30 and the second pressure body 32 contact at least in some areas. In particular, it is shown here that the pressure regulating device 20 can also have a third pressure body 36, wherein a further intermediate plate 38 is formed between the second pressure body 32 and the third pressure body 36. Furthermore, it can be seen that in the present exemplary embodiment, a pressure plate 40 is formed between the third pressure body 36 and one of the battery cells 18.For example, if the battery module housing 22 has only two pressure bodies 30, 32, the pressure plate 40 can be formed between the second pressure body 32 and the battery cell 18. The pressure regulating device 20 can also have more than three pressure bodies 30, 32, 36.

[0036] Fig. 3 shows a further schematic plan view according to the embodiment of Fig. 2 . In Fig. 3 It can be seen that the pressure regulating device 20 has "inflated" the pressure bodies 30, 32, and 36 accordingly, thus adjusting the pressure value, for example, because cell respiration of the battery cells 18 has been carried out. In particular, it can be seen that the pressure bodies 30, 32, and 36 are supported on the module frame 24. Furthermore, the battery cells 18 are also supported on the module frame 24.

[0037] In particular, it can be provided that the first pressure body 30 and / or the second pressure body 32, as well as in this case the third pressure body 36, are formed from a rubber-like material. This aspect is also to be considered an independent aspect of the invention.

[0038] Furthermore, the Fig. 3 that at least the first pressure body 30 and the second pressure body 32 are connected to one another via a fluidic connection 42. Furthermore, in the present exemplary embodiment, the second pressure body 32 is also fluidically connected to the third pressure body 36 via the fluidic connection 42. In particular, it can be provided that the fluidic connection 44 is guided through a recess 44 within the intermediate pressure plate 34.

[0039] Furthermore, the Fig. 3 that a filling valve 46 for fluidically filling the first pressure body 30 and / or the second pressure body 32 is formed on the module frame 24.

[0040] Furthermore, it can be provided that a shape of the first pressure body 30 and / or of the second pressure body 32 at least partially substantially corresponds to the shape of the second receiving area 28, wherein it can further be provided that a cross section of the first pressure body 30 and / or of the second pressure body 32 is substantially oval or substantially round.

[0041] In particular, the Fig. 2 und 3 that a fluid can be pumped into the elastic hoses or pressure bodies 30, 32, 36, whereby the fluid can be either compressible, for example, air, or incompressible, for example, liquid. The pressure bodies 30, 32, 36 are in particular a hose, although other shapes, such as bladders or bellows-shaped elements, are also possible. In the case of the hose, for example, the cross-section can be round or oval. In the case of a hose, the respective open ends can be welded shut, for example.

[0042] The hose itself is not load-bearing and is supported by the module frame 24, which makes it possible to make the hose very thin and flexible, giving it a very high level of deformability. Thanks to the support, the hose can be inflated to significantly higher pressures than it could achieve without a casing, for example. Pressure values ​​of greater than 16 bar can be achieved, whereby comparable materials that are used particularly in the bicycle sector can be used. When the thin hose is inflated, it fills the cavity of the normally rectangular module design. The material is so flexible that the hose adapts to the module geometry. The module cavity is designed so that no sharp edges can damage the hose. Radii are provided in such a way that the hose can fit snugly. Corresponding gaps are kept to a minimum.Another possibility is for the tube to plastically deform during initial inflation, taking on the shape of the module cavity. As already mentioned, the tube shapes are usually oval, but it is also possible to design a tube shape so that the tube expands into a more square shape within the cavity. Furthermore, the tube material can be reinforced at certain points, for example, to protect bends / radii.

[0043] In order to achieve larger strokes, it is possible to insert several hoses one behind the other and separate them with thin plates. These plates are referred to in particular as the intermediate pressure plate 34, which does not fulfill a mechanical supporting role but merely serves as a contact surface between the air hoses so that they do not change shape. If several hoses are connected in series, the hoses are connected in particular via corresponding air connections, for example valves or locking devices, which ensure that the fluid pressure between the hoses is the same. One of the hoses, preferably the one located at the edge of the module, in this case preferably the first pressure body 30, is supplied with the fluid. This valve is a pressure control valve and measures and regulates the pressure in the hoses.The valves and air connections are preferably mounted centrally in the intermediate pressure plates 34 and the pressure bodies 30, 32, 36. The pressure valve makes it possible to control the pressure in the hoses. Without limiting the invention, other valves and connectors may be used depending on the fluid used.

[0044] Since the hoses always fully contact the intermediate pressure plates 34 and the pressure plate 40, which forms the transition to the battery cell 18, it is possible to determine the pressure on the battery cells 18 at any time via the pressure in the hose. This is only possible because the hose is so thin and flexible that it completely fills the cavity and assumes its shape at the slightest pressure. If the material has already undergone plastic deformation after the initial inflation and has assumed the geometry of the cavity, the shape remains unchanged even under very low pressures.

[0045] Fig. 4 shows a schematic perspective view according to one embodiment of a pressure body 30, 32, 36. In the present case, it is shown in particular that the pressure body 30, 32, 36 is substantially rectangular and has adapted to the shape of the battery module housing 22. Furthermore, it is shown that reinforcements 50 are formed, particularly in corresponding corner regions 48, so that damage to the pressure bodies 30, 32, 36 is prevented. This is also an independent aspect of the invention, which can therefore be considered both in conjunction with the two pressure bodies 30, 32 and on its own.

[0046] Fig. 5 shows a schematic perspective view of an embodiment of a battery module 14. In the present case, the module frame 24 is shown in particular. Furthermore, the three pressure bodies 30, 32, 36 are shown. The pressure bodies 30, 32, 36 are each separated from one another by the intermediate pressure plates 34, 38. The pressure plate 18 is again arranged between the third pressure body 36 and the battery cells 18. In the present case, the battery module 14 has a plurality of battery cells 18. In particular, it can be provided that, for example, the battery cells 18 are arranged within a cassette guide 52 so that they can move within the module frame 24 during cell respiration. In other words, the battery cells 18 hang movably in corresponding rails 54 and can expand accordingly depending on cell respiration and pressure regulation. In particular, the Fig. 5Furthermore, the battery cells 18 are supported in particular on a first side wall 56 of the module frame 24, and the first pressure body 30 is supported on a second side wall 58 opposite the first side wall 56. This support, in turn, makes it possible for the corresponding pressure value within the battery module 14 to be adjusted through pressure regulation and the expansion of the battery cells 18.

Claims

1. A battery module housing (22) for a battery module (14, 16) of an electrical energy storage device (12) having at least one battery cell (18), wherein the at least one battery cell (18) undergoes a change in volume in accordance with a cell state, comprising at least one module frame (24) which forms at least one pressure-regulating device (20), a first receiving region (26) for the at least one battery cell (18) and a second receiving region (28) for the at least one pressure-regulating device (20) of the battery module housing (22), wherein the pressure-regulating device (20) can be at least partially in contact with the at least one battery cell (18) in the assembled state of the battery module (14, 16) and is designed to adjust a predetermined pressure value on the battery cell (18) in accordance with the change in volume, wherein the pressure-regulating device (20) has at least one first tube-like and flexible pressure body (30) and a separate second tube-like and flexible pressure body (32), wherein a movable intermediate pressure plate (34) which is at least partially in contact with the first pressure body (30) and the second pressure body (32) is formed between the first pressure body (30) and the second pressure body (32), wherein the first pressure body (30) and / or the second pressure body (32) has a reinforcement (50) at respective edge regions and / or corner regions (48), characterized in that the first pressure body (30) and / or the second pressure body (32) are formed from a rubber-like material.

2. The battery module housing (22) according to claim 1, characterized in that at least the first pressure body (30) and the second pressure body (32) are fluidically connected to one another.

3. The battery module housing (22) according to claim 2, characterized in that at least the first pressure body (30) and the second pressure body (32) are fluidically connected to one another via a fluidic connection (42) which is guided through a recess (44) inside the intermediate pressure plate (40).

4. The battery module housing (22) according to any one of the preceding claims, characterized in that a filling valve (46) for fluidically filling the first pressure body (30) and / or the second pressure body (32) is formed on the module frame (24).

5. The battery module housing (22) according to any one of the preceding claims, characterized in that a shape of the first pressure body (30) and / or of the second pressure body (32) at least partially corresponds to the shape of the second receiving region (28).

6. The battery module housing (22) according to any one of the preceding claims, characterized in that a cross section of the first pressure body (30) and / or of the second pressure body (32) is designed to be oval or round.

7. The battery module (14, 16) for an electrical energy storage device (12) having at least one battery module housing (22) according to any one of claims 1 to 6 and having at least one battery cell (18), wherein the at least one battery cell (18) undergoes a change in volume in accordance with a cell state.

8. An electrical energy storage device (12), in particular for an at least partially electrically operated motor vehicle (10), comprising at least one battery module (14, 16) according to claim 7.