Pressure compensation arrangement for a battery, battery housing, and method for operating a pressure compensation arrangement

Abstract

The invention relates to a pressure equalization arrangement (12) for a battery (10), comprising a pressure equalization element (24) for establishing pressure equalization between an internal pressure (p2) in an interior space (18) and an ambient pressure (p1) in an exterior space (20). The pressure equalization element (24) has an open state in which a fluidic connection is established between the interior space (18) and the exterior space (20), and a closed state (G) in which the pressure equalization element (24) is fluid-tight. The pressure equalization element (24) can be transferred from the closed state (G) to the open state. The pressure equalization arrangement (12) comprises a control device (26) designed to transfer the pressure equalization element (24) from the closed state (G) to the open state depending on at least one pressure-independent first parameter (P2, P3).

Description

[0001] The invention relates to a pressure equalization arrangement for a battery, wherein the pressure equalization arrangement comprises a pressure equalization element for arrangement in a wall separating an interior and an exterior space and for establishing pressure equalization between an internal pressure prevailing in the interior space and an ambient pressure prevailing in the exterior space. The pressure equalization element has an open state in which a direct fluidic connection is established between the interior space and the exterior space, establishing pressure equalization, and a closed state in which the pressure equalization element is fluid-tight, wherein the pressure equalization element can be transferred from the closed to the open state. Furthermore, the invention also relates to a battery housing and a method for operating a pressure equalization arrangement.

[0002] Pressure equalization elements and emergency venting valves are often used in high-voltage batteries, especially for automotive applications. Pressure equalization elements often include a membrane that allows air to pass through but not water. They ensure, for example, that there is no overpressure or underpressure in the battery.

[0003] A pressure equalization device with a waterproof membrane that is breathable and allows air exchange between the interior of the housing and the environment for pressure equalization is described in DE 10 2019 129 611 A1. The pressure equalization device can also have a check valve integrated into a wall of the battery housing to prevent excess pressure from damaging the battery cells. Furthermore, a fan can specifically draw in air or increase the pressure inside the housing.

[0004] Emergency vent valves are often flutter or burst valves that open when a certain excess pressure is reached in the battery case as a result of thermal runaway. These valves protect the battery case from uncontrolled bursting during thermal runaway.

[0005] In most cases, such elements, namely pressure equalization elements and / or emergency venting valves, must be sealed separately during production to perform the leak test at the end of the line, since pressurization performed during the leak test should not cause these valves or elements to open. Furthermore, a pressure equalization element can often also allow humidity to enter the battery, which can condense on cold components.

[0006] DE 10 2021 114 590 A1 describes a device for regulating the internal pressure in a battery housing. A pressure equalization unit with a pump unit is provided, by means of which the internal pressure can be varied depending on the ambient pressure. The pump unit can furthermore have a drying unit to adjust the humidity of a volume flow to a predefined level. In addition, an air volume flow can be introduced from the ambient air into the interior of the battery housing. A vapor barrier is provided between the ambient air and a check valve, which limits the ingress of water vapor into the interior of the battery housing.

[0007] These designs are relatively complex and expensive and also require a lot of installation space and numerous components.

[0008] The object of the present invention is to provide a pressure equalization arrangement, a battery housing and a method which enable pressure equalization in the simplest and most cost-effective manner possible and at the same time allow the best possible adaptation to the situation.

[0009] This object is achieved by a pressure compensation arrangement, a battery housing, and a method having the features according to the respective independent patent claims. Advantageous embodiments are the subject of the dependent patent claims, the description, and the figures.

[0010] A pressure equalization arrangement for a battery according to the invention comprises a pressure equalization element for arrangement in a wall separating an interior and an exterior space and for establishing pressure equalization between an internal pressure prevailing in the interior space and an ambient pressure prevailing in the exterior space. The pressure equalization element has an open state in which a direct fluidic connection is established between the interior space and the exterior space, establishing pressure equalization, and a closed state in which the pressure equalization element is fluid-tight, the pressure equalization element being transferable from the closed to the open state. The pressure equalization arrangement comprises a control device designed to transfer the pressure equalization element from the closed to the open state depending on at least one pressure-independent first parameter.

[0011] The invention is based on the finding that a controllable pressure equalization element allows, on the one hand, significantly better adaptation options to different situations during operation and, for example, also enables a simplified leak test of a battery housing during battery manufacture, since the controllable pressure equalization element does not have to be designed for passive opening in the event of, for example, even small pressure differences and can, for example, be designed to be more robust than a bursting membrane and can therefore be kept closed in such a test situation in a simple manner without additional sealing measures by means of control.Furthermore, the invention is based on the finding that such a controllable pressure compensation element provides the possibility of controlling it not only in a pressure-dependent manner, but also, above all, of taking other parameters, in particular environmental parameters and / or situational parameters, into account. This allows for significantly better adaptation to the situation and a significantly simpler design of the pressure compensation arrangement as a whole. For example, as provided in advantageous further embodiments of the invention, air humidity in the interior and exterior spaces can be taken into account as such a pressure-independent first parameter. This eliminates the need for additional air drying measures.Furthermore, the invention is based on the finding that such a controllable pressure equalization element not only provides improved situational adaptation in normal operating situations, for example to the ambient air humidity prevailing, but can also provide particularly efficient and early pressure reduction in the battery housing in emergency situations, in particular in the event of thermal runaway of a battery cell, for example by preventatively opening it before such a cell outgassing. This then, for example, no additional emergency venting valves are required and components can be saved. By opening it this way, for example, overpressure in the battery housing caused by outgassing from the battery cell cannot build up as quickly or not at all. This prevents backpressure on the outgassing cell.Due to the advantageous control option of the pressure equalization element and the improved situational adaptations it provides, it is also unnecessary, for example, to integrate complex air drying measures into the arrangement and / or to provide complex pumping devices or other air conveying devices, such as fans or the like. In particular, the invention allows pressure equalization to be achieved in a particularly simple manner by converting the pressure equalization element from the closed to the open state, in which a direct fluidic connection between the interior and the exterior is established through the pressure equalization element. Thus, overall, a particularly simple and cost-effective pressure equalization option can be provided, which also allows for particularly good situational adaptation.

[0012] The pressure equalization element is designed for installation in a wall. When the pressure equalization element is in its intended installation position, it is located in a wall, for example, a battery housing. The pressure equalization element thus borders the interior space with one side and the exterior space with the other, opposite side. The fact that the pressure equalization element has an open state, in which a direct fluidic connection is established between the interior and exterior spaces, establishing pressure equalization, is to be understood in relation to the intended installation position in the wall separating the interior and exterior spaces.In the open state, the pressure compensation element can, for example, simply have a hole or opening formed between two mutually movable components encompassed by the pressure compensation element, creating such a fluidic connection between the interior and exterior. This fluidic connection can, in particular, also be permeable to liquids. However, this is unproblematic due to the controllability of the pressure compensation element, as it can be kept closed, for example, when liquids are present in the immediate external environment of the pressure compensation element.

[0013] The external space can also be referred to as the surroundings. The external space can be the surroundings of the battery housing and / or the battery in which the pressure equalization arrangement is used and / or the surroundings of the motor vehicle that includes such a battery housing or such a battery. The battery is preferably a high-voltage battery.

[0014] The battery housing is preferably an overall battery housing in which the battery modules comprised by the high-voltage battery are accommodated.

[0015] The pressure compensation element is designed so that it can be reversibly switched from the closed state to the open state by actuating it with the control device. For example, the pressure compensation element can be designed so that it is in the closed state without actuation and is switched to the open state when actuated. This allows the pressure compensation element to remain closed, for example, when the motor vehicle is not actuated or de-energized. This is particularly energy-efficient.

[0016] Preferably, the pressure compensation element has only the two aforementioned states, namely the open state and the closed state. In the closed state, the pressure compensation element is fluid-tight. In this state, no fluid, in particular neither gas nor liquid, can pass through the pressure compensation element.

[0017] The pressure compensation element can, for example, comprise a spring-loaded valve and an actuator controllable by the control device. The actuator can, for example, be an electrical and / or electromechanical and / or magnetic and / or electromagnetic actuator. The spring-loaded valve comprises a spring element that holds the valve in the closed state with force while the actuator is, for example, in a non-controlled position or closing position or in a non-controlled state or closing state that corresponds to the closed state of the valve. When appropriately controlled, the actuator can counteract the spring force provided by the spring element to open the valve.

[0018] It can also be provided that the actuator reduces the spring force exerted on the valve when activated, for example if a spring end of the spring element is arranged on the actuator, which moves away from the valve together with the spring element when activated.

[0019] In general, the spring element can be designed, for example, as a spiral spring and / or disc spring or the like.

[0020] The control device can be designed to obtain a value of the current first parameter, and in particular optional additional parameters, from a suitable sensor device. Such a sensor device can also be part of the pressure compensation arrangement. For example, such a sensor device can comprise at least one or more humidity sensors and / or pressure sensors and / or TDR (Thermal Runaway Detection) sensors, i.e., sensors for detecting thermal runaway in one or more battery cells. Depending on the measurement signals acquired by the sensor device, the control device can, for example, determine a parameter value and, depending on this, control the pressure compensation element.

[0021] A pressure-independent parameter is understood to be a quantity, e.g., a measured quantity, or a quantity derived or calculated from one or more measured quantities, that does not represent the internal pressure or ambient pressure, in particular, that does not represent a pressure value at all, and for which no such pressure value was used to determine or calculate it. However, the control of the pressure compensation element dependent on a pressure-independent parameter does not imply that the control of the pressure compensation element is entirely pressure-independent.

[0022] According to a further advantageous embodiment of the invention, the pressure compensation element can be transferred from the closed state to the open state depending on a second parameter that depends on the internal pressure and the ambient pressure, in particular passively and / or by actuation by the control device. This advantageously also allows a pressure, namely the internal pressure and the ambient pressure, to be taken into account when opening and closing the pressure compensation element, in particular when actuated by the control device. The control device can therefore be designed to control the pressure compensation element both depending on the first parameter and depending on the second parameter and to transfer it from the closed state to the open state.For example, the control device can perform the activation depending on a pressure difference between the internal pressure and the ambient pressure. The pressure-dependent opening of the pressure compensation element can additionally or alternatively also occur purely passively.

[0023] According to a further advantageous embodiment of the invention, the pressure compensation element is designed such that, at least when the internal pressure is greater than the ambient pressure and a pressure difference between the internal pressure and the ambient pressure is greater than a predetermined maximum pressure threshold, the pressure compensation element is passively and independently of control transferred from the closed state to the open state. In other words, such a passive opening mechanism can also be integrated into the pressure compensation element. This ensures that the pressure compensation element opens when the internal pressure is greater than the ambient pressure by a predetermined minimum value, even if, for example, the control device fails due to a defect or the like. This advantageously provides an emergency pressure compensation option.

[0024] For example, the valve encompassed by the pressure compensation element can comprise a first and a second valve element that are movable relative to one another. The first valve element can, for example, be fixed to the wall, and the second valve element can be movable relative to the first valve element by means of the actuator. The second valve element can, for example, be connected to the actuator. If the actuator is in a closed position associated with the pressure compensation element, a specific spring force is exerted in this position via the spring element on the second valve element in the direction of the first valve element, thereby pressing the second valve element against the first valve element. The pressure compensation element is thus in the closed state and in a fluid-tight state.If the actuator is moved to a specific open position and away from the first valve element, the second valve element is simultaneously moved away from the first valve element. The pressure compensation element is then in the open state. If the actuator is in the closed position and the internal pressure is greater than the external pressure by more than the predetermined differential value, which is defined by the predetermined maximum pressure threshold, the second valve element is moved toward the actuator, further compressing the spring element. In this case, the pressure compensation element can also be opened passively while the actuator remains in the closed position.The pressure compensation element can therefore be designed such that when the actuator is in the closed position and the valve is closed, the spring element is in a tensioned state, but not in a fully tensioned state. For example, it is partially compressed, but not fully compressed.

[0025] According to a further advantageous embodiment of the invention, the at least one first parameter depends on an indoor air humidity prevailing in the interior and an outdoor air humidity prevailing in the exterior, in particular on a humidity difference between the indoor air humidity and the outdoor air humidity. This has the great advantage that such a humidity difference can also be taken into account when opening and closing the pressure equalization element. This can then advantageously be opened, for example, only when the outdoor air humidity in the environment is lower than the indoor air humidity. Thus, the pressure equalization element can also be used to dry the interior through targeted control, for example by opening it even when the outdoor air humidity is lower than the indoor air humidity, even if no pressure equalization is to be provided.In this case, the opening of the pressure compensation element can optionally be time-limited, e.g., the pressure compensation element is only opened for a specific maximum period. Alternatively, the pressure compensation element can also be opened until the outside humidity is equal to or greater than the inside humidity.

[0026] According to a further advantageous embodiment of the invention, the control device is designed to control the pressure compensation element in such a way that it is opened at least temporarily when the outside air humidity is lower than the inside air humidity. This can optionally be linked to further conditions, for example the pressure difference between the inside pressure and the ambient pressure. For example, it can be provided that the pressure compensation element is opened, in particular only opened, when a certain minimum pressure difference exists between the ambient pressure and the inside pressure. On the other hand, it can also be provided that the pressure compensation element is always opened, regardless of the presence of a pressure difference, as soon as the outside air humidity is lower than the inside air humidity or the outside air humidity is lower than the inside air humidity by a predetermined minimum value, or similar.Thus, controlling the pressure compensation element can be advantageously used to dehumidify the interior in a targeted manner. This advantageously requires no additional drying device or similar equipment.

[0027] According to a further advantageous embodiment of the invention, the control device can also be designed to control the pressure compensation element in such a way that it is not opened, at least not opened by control, if the outside air humidity is greater than the inside air humidity and optionally the pressure difference fulfills a predetermined first criterion, which at least comprises that an amount of the pressure difference is less than a predetermined first pressure threshold, and in particular a further optional second criterion is fulfilled. The first pressure threshold can be, for example, the aforementioned predetermined maximum pressure threshold. This means that if this predetermined maximum pressure threshold is exceeded, the pressure compensation element opens in any case, be it passively or actively by control, in particular regardless of the air humidity prevailing outside or inside.This advantageously ensures that an excessive pressure difference does not lead to damage to the housing in which the pressure compensation element is installed. However, the first pressure threshold can also be set lower than the aforementioned maximum pressure threshold, above which the pressure compensation element automatically opens passively, for example. Therefore, as long as the pressure difference is sufficiently small and the outside air humidity is higher than the inside air humidity, the pressure compensation element is preferably not opened. This advantageously prevents additional air humidity from entering the interior.

[0028] According to a further variant, the control device can also be configured to actuate the pressure compensation element in such a way that it is not opened, at least not opened by actuation, when the outside air humidity is greater than the inside air humidity, regardless of a pressure difference. Thus, the pressure compensation element can also be kept closed as long as the outside air humidity is greater than the inside air humidity. This can effectively prevent moisture from penetrating the interior.

[0029] As already mentioned above, this can occur, for example, under the optional additional condition that a second criterion is met. This could, for example, consist in the fact that no emergency situation, such as an abnormal battery condition, in particular a thermal runaway of a battery cell, is detected. In such a condition, the pressure compensation element can be opened independently of a humidity difference and / or even independently of a pressure difference, as explained in more detail later, and thus simultaneously function as an emergency venting valve.

[0030] Therefore, if no such emergency situation exists, the pressure compensation element can be controlled in such a way that it is opened when the outside air humidity is lower than the inside air humidity, and if not, it remains closed, at least if the pressure difference meets a predetermined criterion and, in particular, does not exceed the above-mentioned first pressure threshold.

[0031] There are numerous other control options for the pressure compensation element to optimize its opening and closing depending on the internal and external pressures, as well as the corresponding air humidity levels and / or other parameters. Especially when the pressure difference is less than a predetermined threshold, for example, the aforementioned maximum pressure threshold or the first pressure threshold, there are various options for opening and / or closing the pressure compensation element depending on the air humidity difference.For example, it can be provided that the control device is designed to control the pressure compensation element in such a way that, in the event that an amount of the pressure difference is less than at least a second pressure threshold, the pressure compensation element is transferred to the open state, in particular is transferred to the open state only when the outside air humidity is lower than the inside air humidity and / or an amount of the air humidity difference between the inside air humidity and the outside air humidity falls below a predetermined first limit value. It can therefore also be provided that, with a sufficiently small pressure difference, opening is only provided when the outside air humidity is lower than the inside air humidity or at least when the air humidity difference is not excessively large.The outside air humidity may then be higher than the inside air humidity, but only slightly, for example. For example, it may also be provided that the pressure threshold at which the control device causes the pressure compensation element to open is determined depending on the current air humidity difference and, in particular, the sign of the air humidity difference. If, for example, the outside air humidity is significantly higher than the inside air humidity, the pressure threshold at which the pressure compensation element opens can be selected to be higher than if, for example, the outside air humidity is only slightly higher than the inside air humidity or even lower than the inside air humidity.

[0032] A further boundary condition for opening the pressure compensation element can be, for example, that there is no liquid in the area of ​​the pressure compensation element, in particular that the pressure compensation element is not currently immersed in a liquid in the external space. This can prevent liquid from entering the interior in the event that the pressure compensation element is, for example, partially or completely submerged.

[0033] According to a further advantageous embodiment of the invention, the pressure compensation arrangement comprises at least one first humidity sensor for detecting the outside air humidity and / or at least one second humidity sensor for detecting the inside air humidity. The control device can be coupled to these humidity sensors in order to receive their measurement signals and, depending on them, to control the pressure compensation element. The outside air humidity sensor can be arranged on the outside of the housing or at any desired position outside the housing, while the inside air humidity sensor is preferably arranged inside the housing when the pressure compensation arrangement is in its intended installation position on the pressure compensation element in the wall of a housing.

[0034] According to a further very advantageous embodiment of the invention, the at least one first parameter or a third parameter, depending on which the control device controls the pressure compensation element to open it, is a detected abnormal battery condition. If such an abnormal battery condition is detected, which can also be detected with a suitable sensor device, the control device then opens the pressure compensation element. This advantageously makes it possible, especially in the event of thermal runaway of a battery cell, to open the pressure compensation element, for example, before the battery cell outgasses as a result of the thermal runaway. As a result, a pressure increase caused by such outgassing can be reduced early on or avoided entirely.

[0035] Accordingly, a further highly advantageous embodiment of the invention is provided if the pressure compensation arrangement has at least one sensor for detecting the abnormal battery condition, which is designed to detect a thermal runaway of a battery cell of the battery as the abnormal battery condition, in particular before gas escapes from the battery cell. This advantageously enables early opening of the pressure compensation element.

[0036] The sensor can, for example, be designed as a temperature sensor for detecting the cell temperature of the battery cells. If an excessive temperature increase occurs, for example, if a temperature limit is exceeded, thermal runaway of such a battery cell or an impending thermal runaway can be considered detected. The sensor can also be designed as a current and / or voltage sensor for detecting a cell voltage and / or a cell current or battery current or battery voltage. This allows, for example, electrical anomalies, such as short circuits, to be detected, which can provide an indication of impending thermal runaway of such a battery cell.The sensor can also be designed to detect mechanical force being applied to the battery and / or for intrusion detection or similar in order to detect mechanical damage to the battery or cells, which can also lead to thermal runaway of the cells. The sensor can furthermore comprise a gas sensor to detect outgassing from the at least one battery cell of the battery. In this case, although the abnormal battery condition cannot be detected before gas escapes from the battery cell, this can still ensure that the pressure compensation element can be opened in a timely manner. In particular, this can also ensure that the pressure compensation element can be opened early enough that a particularly high overpressure has not yet built up in the battery housing due to the gas escape.

[0037] Furthermore, the invention also relates to a battery housing with a pressure compensation arrangement according to the invention or one of its embodiments. The advantages mentioned for the pressure compensation arrangement according to the invention and its embodiments apply equally to the battery housing according to the invention.

[0038] Furthermore, the battery housing can comprise the wall in which the pressure compensation element is arranged. The battery housing can enclose the interior space. In particular, the wall of the battery housing can enclose the interior space of the battery housing and separate it from the exterior space, in particular from an environment, and hermetically seal it, at least when the pressure compensation element is closed. The above-mentioned at least one sensor for detecting the abnormal battery state can be arranged within the battery housing, i.e., in the interior space. The control device for controlling the pressure compensation element can be arranged in the interior space or the exterior space. In the case of the above-mentioned humidity sensors and / or pressure sensors, at least one is arranged in the interior space and at least one in the exterior space.

[0039] Furthermore, the invention also relates to a battery with a battery housing according to the invention or one of its embodiments. Furthermore, the invention also relates to a battery with a pressure compensation arrangement according to the invention or one of its embodiments.

[0040] The battery can be designed, for example, as a high-voltage battery. The battery can comprise the battery housing in which one or more battery modules are arranged. Such a battery module can further comprise one or more battery cells. These can be designed, for example, as lithium-ion cells.

[0041] Furthermore, the invention also relates to a motor vehicle with a battery according to the invention or one of its embodiments.

[0042] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

[0043] Furthermore, the invention relates to a method for operating a pressure equalization arrangement, wherein a pressure equalization element is arranged in a wall separating an interior and an exterior space, and has an open state in which a direct fluidic connection is established between the interior and the exterior space, by means of which a pressure equalization is established between an internal pressure prevailing in the interior and an ambient pressure prevailing in the exterior space, and has a closed state in which the pressure equalization element is fluid-tight. In this process, the pressure equalization element is transferred from the closed to the open state. Furthermore, the pressure equalization arrangement comprises a control device which transfers the pressure equalization element from the closed to the open state depending on at least one pressure-independent first parameter.

[0044] Here too, the advantages described for the pressure compensation arrangement according to the invention and its embodiments apply equally to the method according to the invention.

[0045] For use cases or application situations that may arise during the method and which are not explicitly described here, it may be provided that, in accordance with the method, an error message and / or a request to enter user feedback is issued and / or a default setting and / or a predetermined initial state is set.

[0046] The invention also includes the control device for the pressure compensation arrangement. The control device can have a data processing apparatus or a processor device that is configured to carry out an embodiment of the method according to the invention. For this purpose, the processor device can have at least one microprocessor and / or at least one microcontroller and / or at least one FPGA (Field Programmable Gate Array) and / or at least one DSP (Digital Signal Processor). In particular, a CPU (Central Processing Unit), a GPU (Graphical Processing Unit), or an NPU (Neural Processing Unit) can be used as the microprocessor. Furthermore, the processor device can have program code that is configured to carry out the embodiment of the method according to the invention when executed by the processor device. The program code can be stored in a data memory of the processor device.The processor device can, for example, be based on at least one circuit board and / or on at least one SoC (System on Chip).

[0047] The invention also includes further developments of the method according to the invention which have features as have already been described in connection with the further developments of the pressure compensation arrangement according to the invention and the battery housing according to the invention.

[0048] For this reason, the corresponding developments of the method according to the invention are not described again here.

[0049] The invention also encompasses combinations of the features of the described embodiments. The invention therefore also encompasses implementations that each comprise a combination of the features of several of the described embodiments, unless the embodiments are described as mutually exclusive.

[0050] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 is a schematic representation of a battery with a pressure equalization arrangement according to an embodiment of the invention; and Fig. 2 a schematic representation of a pressure compensation element for a pressure compensation arrangement according to an embodiment of the invention.

[0051] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that can be considered independently of one another, each of which also develops the invention independently of one another. Therefore, the disclosure is intended to encompass combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0052] In the figures, the same reference symbols designate elements with the same function.

[0053] Fig. 1 shows a schematic representation of a battery 10 with a pressure equalization arrangement 12 according to an exemplary embodiment of the invention. The battery 10 can be designed, for example, as a high-voltage battery, in particular for a motor vehicle. The battery 10 comprises a housing 14 having a wall 16 that separates an interior space 18 of the housing 14 from an environment 20, which can also be referred to as the exterior space 20. Battery cells 22 of the battery 10 are arranged in the interior space 18.

[0054] The pressure equalization arrangement 12 comprises a pressure equalization element 24, which is arranged in the wall 16 of the battery housing 14. The pressure equalization element 24 is designed to establish a pressure equalization between the ambient pressure p1 prevailing in the environment 20 and the internal pressure p2 prevailing in the interior 18. The pressure equalization arrangement 12 further comprises a control device 26 for controlling the pressure equalization element 24. The pressure equalization element 24 can therefore be controlled by the control device 26 from a closed state G (cf. Fig. 2) into an open state and vice versa. The control device 26 is designed to control the pressure compensation element 24 as a function of a plurality of parameters, the three parameters P1, P2, P3 being shown here as examples. In particular, the control device 26 is designed to control the pressure compensation element 24 as a function of a pressure parameter P1, e.g. a pressure difference P1 between the internal pressure p2 and the external pressure p1. This pressure parameter P1 represents an example of the parameter previously referred to as the second parameter. For this purpose, the pressure compensation arrangement 12 or the battery 10 can comprise a first pressure sensor 28 which is designed to detect the ambient pressure p1.In the present example, this is arranged on the battery housing 14 or on the wall 16, but can in principle be arranged at any other location in the exterior space or in the area of ​​the environment 20. Furthermore, the battery 10 or the pressure compensation arrangement 12 comprises a second pressure sensor 30, which is arranged in the interior space 18 and is correspondingly designed to detect the internal pressure p2. The detected measured values ​​p1, p2 can then be provided to the control device 26. This can use this to determine, for example, the pressure difference P1 or another variable, e.g. a pressure ratio or the like, and control the pressure compensation element 24 depending on this pressure parameter P1, e.g. the pressure difference P1.

[0055] Furthermore, the control device 26 can be configured to control the pressure compensation element 24 as a function of an air humidity parameter P2, e.g., an air humidity difference P2, as an example of a first parameter. The air humidity difference P2 can represent a difference between an air humidity f2 prevailing in the interior 18, which can be detected by a humidity sensor 32 of the battery 10 or the pressure compensation arrangement 12 arranged in the interior 18, and an air humidity f1 prevailing in the environment 20, which can be detected by a humidity sensor 34 arranged in the environment 20. These detected measured values ​​f1, f2 are also provided to the control device 26 for determining the first parameter P2.The measured values ​​recorded, both by the pressure sensors 28, 30 and by the humidity sensors 34, 32, can be provided to the control device 26 repeatedly, for example, at predetermined time intervals and / or quasi-continuously. This allows for permanent pressure and humidity monitoring, and the control device 26 can appropriately control the pressure compensation element 24 depending thereon. If the air humidity outside the high-voltage battery compartment, i.e., outside the interior 18, is lower than in the high-voltage battery compartment 18, the valve 24 can be opened. If the air humidity outside the high-voltage battery compartment 18 is higher than in the high-voltage battery compartment 18, the valve 24 remains closed, for example, in particular, for example, at least as long as the pressure difference P1 is smaller than a maximum threshold value.

[0056] Furthermore, it is advantageous if the control device 26 is designed to open the valve 24 upon positive thermal runaway detection as a further example of the first parameter or an additional third parameter. For this purpose, the battery 10 or the pressure equalization arrangement 12 can comprise at least one further sensor 36, for example also in the interior 18, which is designed to record a specific measured variable A, based on which an abnormal state of the battery 10, for example of one of the battery cells 22, can be detected. This measured variable A can be, for example, a cell temperature, a cell voltage or battery voltage, a cell current or battery current, a gas concentration of a specific gas and / or a gas composition of the gas present in the interior 18, or the like. This measured variable A can also be recorded repeatedly and provided to the control device 26.Based on this measured variable A, the control device 26 can, for example, detect an abnormal condition of the battery 10 or the cells 22 represented by the parameter P3, for example, a thermal runaway of one of the cells 22 or an impending or incipient thermal runaway of the cells 22. If such a thermal runaway, also referred to as thermal runaway, is detected, the control device 26 can control the valve 24 to open it. Thus, the valve 24 can be used not only in a specially adapted manner for pressure equalization during conventional battery operation, but also as an emergency venting valve.

[0057] Furthermore, the battery 10 can also comprise a plurality of such valves 24. These can be arranged at any position on the housing 14 or its wall 16. The provision of, for example, at least two such valves 24 or generally two such pressure equalization elements 24 makes it possible, for example, to provide improved flow of ambient air through the interior space 18, for example for the purpose of drying the interior space 18.

[0058] Fig. 2 shows a schematic representation of a pressure compensation element 24 for a pressure compensation arrangement 12 according to an exemplary embodiment of the invention. The pressure compensation element 24 is, as previously described, arranged, for example, in a wall 16 of a battery housing 14, of which only a part is shown here. The wall 16 has a through-opening 38 for this purpose. The valve 24 is now divided into several individual parts. This comprises a nozzle part 24a, which is designed, for example, with a nozzle 40 arranged within the opening 38 and a fastening flange 42 surrounding the latter, which rests on the outside of the wall 16 and is arranged and fastened to the housing 14 or the wall 16 via a sealing ring 24b as part of the valve 24 in a sealed manner. The valve 24 also comprises a support section 24c. This support section is fastened to the nozzle part 24a and is not movable relative to it.This section 24c, like the sealing ring 24b and the nozzle part 24a, is arranged and fixed to the wall 16. This support section 24c acts as a support and stop for the actuator 24d as a further part of the valve 24. The support section 24c, which can also be referred to simply as support 24c, can, for example, define a closed position S of the actuator 24d, as shown in FIG. Fig. 2. The actuator 24d has a minimal distance from the wall 16 and from the stationary valve part 24', which can comprise the nozzle part 24a, the sealing ring 24b and the support element 24c. In addition to the stationary part 24', the valve 24 also comprises a movable part 24", which comprises a closure element 24e. This is shaped such that in the closed position G of the valve 24, as shown in Fig. 2, closes the opening 38' of the nozzle part 24a in a fluid-tight manner. For this purpose, a corresponding sealing element can be provided either on the outside of the nozzle part 24a or on the inside of the closure part 24e or at any desired location between the closure part 24e and the nozzle part 24a, which, however, is not explicitly shown here. The closure element 24e is also formed with a central, pin-shaped guide element 44, which protrudes from the closure element 24e in the illustrated z-direction, which corresponds to an opening direction of the valve 24, and is thus directed away from the stationary part 24' of the valve 24. The guide element 44 can be guided through a corresponding opening 46 in the support element 24c. The actuator 24d can be arranged on this guide element and, in particular, can be fastened in such a way that it is immovable relative to this guide element 44 with respect to the z-direction.The actuator 24d may have a through-opening 48 through which the guide element 44 is at least partially inserted and / or passed through and / or screwed in or the like.

[0059] Furthermore, the valve 24 comprises a spring element 50. This is supported on the one hand on the upper side on the cover element 24e or closure element 24e, and on the other hand on the inside on the carrier element 24c, that is, on a side of the carrier element 24c opposite the actuator 24d.

[0060] If the actuator 24d is moved upward, i.e., in the z-direction, for example, by control by the control device 26, the closure element 24e is moved upwards and thus away from the stationary part 24' of the valve 24, thereby opening the valve 24. The spring element 50 is compressed in the process. If the force applied to the actuator 24d, which moved it in the z-direction, is removed, the actuator 24d is moved back in the opposite direction by the spring force 50, and the closure 24e closes the opening 38' of the nozzle part 24a. The valve 24 is then again in the closed state G.

[0061] The actuator 24d can be moved in the z-direction by suitable control by the control device 26. This can be done, for example, magnetically and / or electrically and / or electromechanically and / or electromagnetically. The actuator 24d can therefore be controlled electromotively, electrically, magnetically, and so on. Thus, it is advantageously possible to move the valve 24 depending on the Fig. 1 described parameters P1, P2, P3. The valve 24, which in this example is spring-loaded, can be opened via the actuator 24d. In this case, the opening is released by the control unit 26 in conjunction with humidity sensors 32, 34 and thermal runaway detection sensors 36.

[0062] This design of the valve 24 also has the great advantage that it is possible to open the valve 24 independently of a control signal, for example, if the internal pressure p2 exceeds a predetermined limit value that is so great that this internal pressure p2 can overcome the spring force exerted by the spring 50 on the closure part 24e. This makes it possible to open the valve 24 even without moving the actuator 24d. This also provides the option of emergency opening the valve 24, for example, if the control device 26 fails or there is another defect that prevents the actuator 24d from being actively moved. This advantageously allows both an active opening option via control signal and a passive opening option without control signal to be implemented in this valve 24.

[0063] The example is merely illustrative, and the described mode of operation is also possible using a differently designed or modified valve 24 and / or a differently designed actuator 24d that interacts differently with the movable valve part 24" or the closure element 24e. For example, the actuator 24d can comprise an electromagnet that, when energized, attracts the movable valve part 24", in particular the closure element 24e, and thereby opens the valve 24. In this case, no guide element 44 is required, and the actuator 24d itself does not have to comprise a movable element or does not have to be movable itself. The actuator 24d is then also not to be understood as part of the movable valve part 24".

[0064] Overall, the examples demonstrate how active pressure equalization can be provided by the invention. Pressure equalization elements and / or emergency venting valves can be replaced by one or more active valves with a controller. The valve can be controlled in combination with, for example, humidity and TDR (Thermal Runaway Detection) sensors, i.e., sensors for detecting thermal runaway in one or more battery cells. This advantageously allows the valve to be opened early upon detection of thermal runaway, preventing pressure in the battery from building up in the first place. Furthermore, the cell experiencing thermal runaway during thermal runaway experiences no counterpressure during outgassing. The pressure in such a thermally runaway cell can thus be reduced even more efficiently. Furthermore, the high-voltage battery can optionally also be actively dried.In addition, the valve at the end of the belt can be kept closed and does not need to be sealed separately for an overpressure test of the battery housing. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2019 129 611 A1

[0003] DE 10 2021 114 590 A1

[0006]

Claims

[1] Pressure compensation arrangement (12) for a battery (10), comprising - a pressure equalisation element (24) for arrangement in a wall (16, 14) separating an interior space (18) and an exterior space (20) and for establishing a pressure equalisation between an interior pressure (p2) prevailing in the interior space (18) and an ambient pressure (p1) prevailing in the exterior space (20), - wherein the pressure compensation element (24) has an open state in which a direct fluidic connection is established between the interior space (18) and the exterior space (20) to establish pressure compensation, and a closed state (G) in which the pressure compensation element (24) is fluid-tight, - wherein the pressure compensation element (24) can be transferred from the closed state (G) to the open state, characterized bythat the pressure compensation arrangement (12) comprises a control device (26) which is designed to transfer the pressure compensation element (24) from the closed state (G) to the open state as a function of at least one pressure-independent first parameter (P2, P3). [2] Pressure compensation arrangement (12) according to claim 1, characterized by that the pressure compensation element (24) can be transferred from the closed state (G) to the open state, in particular passively and / or by control by the control device (26), as a function of a second parameter (P1) which is dependent on the internal pressure (p2) and the ambient pressure (p1). [3] Pressure compensation arrangement (12) according to one of the preceding claims, characterized bythat the pressure compensation element (24) is designed such that, at least when the internal pressure (p2) is greater than the ambient pressure (p1) and an amount of a pressure difference between the internal pressure (p2) and the ambient pressure (p1) is greater than a predetermined maximum pressure threshold value, the pressure compensation element (24) is transferred passively and independently of a control from the closed state (G) to the open state. [4] Pressure compensation arrangement (12) according to one of the preceding claims, characterized by that the pressure-independent first parameter (P2) depends on an internal air humidity (f2) prevailing in the interior space (18) and an external air humidity (f1) prevailing in the exterior space (20), in particular on an air humidity difference between the internal air humidity (f2) and the external air humidity (f1). [5] Pressure compensation arrangement (12) according to claim 4, characterized bythat the control device (26) is designed to control the pressure compensation element (24) in such a way that - it is opened at least temporarily when the outside air humidity (f1) is lower than the inside air humidity (f2), and - it is not opened if the outside air humidity (f1) is greater than the inside air humidity (f2) and the pressure difference between the inside pressure (p2) and the ambient pressure (p1) satisfies a predetermined first criterion, which at least comprises that an amount of the pressure difference is smaller than a predetermined first pressure threshold value, and in particular a further second criterion is satisfied. [6] Pressure compensation arrangement (12) according to one of the preceding claims, characterized by that has at least one first humidity sensor (34) for detecting the outside air humidity (f1) and at least one second humidity sensor (32) for detecting the inside air humidity (f2). [7] Pressure compensation arrangement (12) according to one of the preceding claims, characterized by that the at least one first parameter (P3) or a third parameter (P3) is a detected abnormal battery condition. [8] Pressure compensation arrangement (12) according to one of the preceding claims, characterized by in that the pressure compensation arrangement (12) has at least one sensor (36) for detecting the abnormal operating state, which sensor is designed to detect, as the abnormal battery state, a thermal runaway of a battery cell (22) of the battery (10), in particular before a gas escapes from the battery cell (22). [9] Battery housing (14) with a pressure compensation arrangement (12) according to one of the preceding claims characterized by that the battery housing (14) comprises the wall (16) in which the pressure compensation element (24) is arranged. [10] Method for operating a pressure compensation arrangement (12), - wherein a pressure compensation element (24) is arranged in a wall (16, 14) separating an interior space (18) and an exterior space (20), - wherein the pressure compensation element (24) has an open state in which a direct fluidic connection is established between the interior space (18) and the exterior space (20), by means of which a pressure equalization is established between an internal pressure (p2) prevailing in the interior space (18) and an ambient pressure (p1) prevailing in the exterior space (20), and a closed state (G) in which the pressure compensation element (24) is fluid-tight, - wherein the pressure compensation element (24) is transferred from the closed state (G) to the open state, characterized bythat the pressure compensation arrangement (12) comprises a control device (26) which transfers the pressure compensation element (24) from the closed to the open state as a function of at least one pressure-independent first parameter (P2, P3).

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