Device and method for detecting a defect in a battery arrangement for a vehicle and battery arrangement for a vehicle

Abstract

The present invention relates to a device (200) and a method for detecting a defect in a battery arrangement (100) and to a battery arrangement (100) which comprises a battery housing (110) and at least one battery cell (120) arranged in the battery housing (110). The device (200) according to the invention has: a first gas sensor (210) which is designed to produce a first gas signal which indicates the presence and / or the content of a gas component within the battery housing (110); a second gas sensor (220) which is designed to produce a second gas signal which indicates the presence and / or the content of the gas component outside the battery housing (110); and a control apparatus (230) which is designed to detect a defect in the battery arrangement (100) when the first gas signal indicates the presence and / or a content of the gas component within the battery housing (110) that exceeds a predetermined first content threshold value and the second gas signal indicates the absence and / or a content of the gas component outside the battery housing (110) that falls below a predetermined second content threshold value.

Description

[0001] Description

[0002] Device and method for detecting a defect in a battery arrangement for a vehicle and battery arrangement for a vehicle

[0003] The present invention relates to a device and a method for detecting a defect in a battery arrangement for a vehicle, in particular the presence of battery cell outgassing and / or thermal runaway of at least one battery cell, as well as to a battery arrangement for a vehicle.

[0004] Lithium-ion batteries are currently used in electromobility, both in hybrid and fully electric vehicles. Lithium-ion batteries use aluminum electrodes on the cathode side and copper electrodes on the anode side as current collectors, usually in foil form. Lithium transition metal oxides, such as cobalt, manganese, and nickel, are used as the cathode material, and carbon / graphite is used as the anode material. The electrolyte in between consists of an organic solvent with dissolved electrolyte salts. To prevent short circuits, a separator permeable to lithium ions (e.g., made of polypropylene) can be placed between the electrodes.

[0005] Crucial for long-term operation is both ensuring that the battery cells are not overcharged and overdischarged, as this can lead to accelerated aging, deactivation of the active components of the electrodes, an increase in cell impedance, and even thermal runaway of the respective cell, i.e., total failure. For this, knowing the current state of charge is crucial.

[0006] When operating lithium-ion batteries, it is important to operate the battery within the correct temperature range. Overheating of the battery is considered particularly dangerous, as beyond a critical temperature, it can lead to unstoppable thermal runaway. This causes the individual components of the battery cell to react uncontrollably with each other. The cell reacts with very strong heat and gas formation until all components have reacted.

[0007] During thermal runaway, gas is formed within the battery cell, and the internal pressure rises to the point where the battery cell casing gives way and ruptures. This causes the generated gas to escape. The battery cell continues to heat up until the uncontrollable reaction begins and the battery cell suddenly fails.

[0008] The gases produced and released can include hydrogen, carbon dioxide, carbon monoxide, and hydrocarbons such as methane or ethane. Depending on the progress of the reaction and thus the thermal runaway, characteristic gas concentrations can be measured, which can provide information about the battery's condition.

[0009] Consequently, the information that a specific gas is present inside the battery casing is important, on the one hand, for detecting whether an ignitable gas mixture is present inside the battery casing, and on the other hand, for detecting thermal runaway in at least one of the battery cells at an early stage. Furthermore, in the case of slow (cold) outgassing, additional information about the condition of the battery cells could be obtained. In conjunction with other sensors of the battery management system (voltage / current sensors), a more precise diagnosis of the condition of the battery or individual cells could be made.

[0010] Future monitoring systems will therefore use one or more different gas sensors that are energized continuously or at significant intervals and can thus detect the gas concentrations within the battery housing. The gas sensor can thus permanently or cyclically detect the composition of the gas or gas mixture present within the battery housing and emit a gas signal on the basis of which the battery's condition can be assessed. Today's battery housings usually have a pressure equalization valve to at least partially compensate for the influence of different ambient pressures and / or temperatures on the pressure within the battery housing. Any gases and gas mixtures can flow out of and into the battery housing via the pressure equalization valve.Thus, a gas sensor located inside the battery housing would generate a gas signal even if a gas component detectable by the gas sensor flows into the battery housing from outside. In such a case, the evaluation of the gas signal from the gas sensor located inside the battery housing would falsely indicate a defect in the battery assembly, such as outgassing from one of the battery cells or the onset of thermal runaway.

[0011] The present invention is essentially based on the object of providing a device and a method with which a defect in a battery arrangement for a vehicle can be detected in a simple, inexpensive and reliable manner.

[0012] This object is achieved with a device according to claim 1, a battery arrangement according to claim 12 and a method according to claim 13. Advantageous embodiments are specified in the subclaims.

[0013] The present invention is essentially based on the idea of ​​equipping a battery assembly with a device having two gas sensors. Each of the two gas sensors is designed to detect the presence and / or content of at least one gas component, with one of the two gas sensors detecting the presence and / or content of the gas component within the battery housing of the battery assembly, and the other of the two gas sensors detecting the presence and / or content of the gas component outside the battery housing. The gas signal from the gas sensor arranged inside the battery housing can thus be verified for plausibility with the gas signal from the gas sensor arranged outside the battery housing.This allows, for example, a warning that a defect in the battery assembly exists, such as thermal runaway of one of the battery cells of the battery assembly, to be issued with greater reliability. In particular, the invention takes advantage of the fact that the battery housing of battery assemblies is usually provided with pressure equalization devices, by means of which pressure equalization and thus fluid flow between the exterior and interior of the battery housing is enabled. Thus, if the gas component flows from outside the battery housing into the battery housing, this can be detected by a signal from each of the two gas sensors, preventing a warning from being issued.In particular, this can avoid a warning to the driver of the vehicle, since despite the gas signal of the gas sensor arranged inside the battery housing, a warning is not given, since due to the detection of the presence of the gas component outside the battery housing, it can be determined that the gas components do not originate from a defect in the battery assembly, but rather have flowed in from outside.

[0014] Consequently, according to a first aspect of the present invention, a device for detecting a defect in a battery assembly is disclosed, which comprises a battery housing and at least one battery cell arranged in the battery housing.The device according to the invention has a first gas sensor which is designed to be sensitive to at least one gas component present within the battery housing and to generate a first gas signal which indicates the presence and / or the content of the gas component within the battery housing, a second gas sensor which is designed to be sensitive to the at least one gas component present outside the battery housing and to generate a second gas signal which indicates the presence and / or the content of the gas component outside the battery housing, and a control device which is connected to the first gas sensor and the second gas sensor and is designed to receive the first gas signal and the second gas signal.The control device is further configured to detect a defect in the battery arrangement if the first gas signal indicates the presence and / or a content of the gas component within the battery housing that exceeds a predetermined first content threshold, and the second gas signal indicates the absence and / or a content of the gas component outside the battery housing that falls below a predetermined second content threshold.

[0015] According to the invention, when a gas component is detected within the battery housing, the gas signal from the first gas sensor is checked for plausibility with the gas signal from the second gas sensor. If the detected gas component is also present outside the battery housing within a very short time before the presence of the gas component is detected inside the battery housing, it can be assumed that the origin of the gas component lies outside the battery housing and, consequently, there is no defect in the battery arrangement, in particular in the at least one battery cell. Rather, it can be assumed that the gas component detected within the battery arrangement with the first gas sensor flowed into the battery housing from outside.

[0016] In a preferred embodiment, the device according to the invention further comprises a device housing in which the first gas sensor and the second gas sensor are at least partially arranged and which is designed to be attached to the battery housing in such a way that an opening provided in the battery housing is at least partially hermetically sealed by the device housing.

[0017] The device housing can form part of the battery housing and can respectively arrange the first gas sensor and the second gas sensor relative to each other such that the first gas sensor detects the gas component inside the battery housing and the second gas sensor detects the gas component outside the battery housing.

[0018] In such a preferred embodiment, it may further be advantageous for the device according to the invention to further comprise a circuit board arranged in the device housing, to which the first gas sensor and the second gas sensor are electrically connected. The circuit board is also electrically connected to the control device, preferably via a suitable connector arrangement.

[0019] Furthermore, in an advantageous embodiment, it is preferred if the first gas sensor extends sealingly from the interior of the device housing at least partially into the interior of the battery housing, and / or if the second gas sensor extends sealingly from the interior of the device housing into the surroundings of the device housing and the battery housing.

[0020] This ensures, in particular, that the first gas sensor detects the gas component inside the battery housing and the second gas sensor detects the gas component outside the battery housing.

[0021] In a further preferred embodiment, the device according to the invention further comprises a pressure compensation device which is designed to at least partially compensate for a pressure difference between the interior of the battery housing and the exterior of the battery housing and to ventilate or vent the battery housing.

[0022] In particular, a fluid flow, for example, ambient air, can flow into the battery housing through the pressure compensation device and out of the battery housing. The device according to the invention can thus additionally have the function of a pressure compensation device and provide ventilation or venting to the battery housing. Consequently, an at least partially compact device can be created that can provide the first gas sensor, the second gas sensor, and the pressure compensation device for the battery arrangement.

[0023] In such an advantageous embodiment, it is further preferred according to a further embodiment that the pressure compensation device is arranged on the device housing in such a way that the fluid flowing out of the battery housing or flowing into the battery housing flows at least partially past the second gas sensor and can be measured by the latter.

[0024] According to a further preferred embodiment, the device according to the invention further comprises an emergency venting device which is designed to vent the battery housing when the pressure inside the battery housing exceeds a predetermined pressure threshold value.

[0025] The emergency venting device can, for example, be designed as a so-called rupture disc, which is arranged in an opening in the device housing. When the predetermined pressure threshold within the battery housing is exceeded, the rupture disc breaks, allowing the gas mixture accumulated inside the battery housing to flow quickly and efficiently out of the interior of the battery housing through the opening then present.

[0026] This can, for example, prevent the battery casing from exploding.

[0027] In this case, it may be particularly preferred that the emergency venting device is arranged on the device housing in such a way that the fluid flowing out of the battery housing through the emergency venting device flows at least partially past the second gas sensor. This, in turn, ensures that the fluid flowing out of the battery housing through the emergency venting device can be measured by the second gas sensor.

[0028] According to a further preferred embodiment, the device according to the invention further comprises a flow guide device which is attached to the device housing and extends at least partially into the interior of the battery housing such that the fluid flowing out of the battery housing through the pressure compensation device and / or emergency venting device is at least partially guided past the first gas sensor.

[0029] The flow guide device can therefore ensure that the fluid present in the battery housing cannot flow out of the battery housing undetected by the first gas sensor. If, for example, there is a defect in the battery assembly, such as in at least one battery cell, the first gas sensor can detect the potentially present gas component with a high degree of reliability.

[0030] In a further preferred embodiment, the device according to the invention further comprises a device flange attached to the device housing, by means of which the device housing can be fastened to the battery housing. The flange can, for example, be projections projecting outward from the battery housing, which, after the device housing has been inserted into the opening provided in the battery housing, are supported on the outer wall of the battery housing and provide a connection option to the battery housing.

[0031] In a further preferred embodiment of the device according to the invention, the device housing has a first housing region which is fluidly connected to the interior of the battery housing, and a second housing region which is fluidly connected to the exterior of the battery housing and is separated from the first housing region by means of a housing wall.

[0032] According to a further aspect of the present invention, a battery arrangement for a vehicle is disclosed, which comprises a battery housing in which at least one battery cell is arranged, and a device according to the invention.

[0033] According to yet another aspect of the present invention, a method for detecting a defect in a battery assembly is disclosed, comprising a battery housing and at least one battery cell arranged in the battery housing. Furthermore, a first gas sensor is provided, which is configured to be sensitive to at least one gas component present within the battery housing and to generate a first gas signal indicating the presence and / or content of the gas component within the battery housing, and a second gas sensor is provided, which is configured to be sensitive to the at least one gas component present outside the battery housing and to generate a second gas signal indicating the presence and / or content of the gas component outside the battery housing.The method according to the invention comprises generating a first gas signal by means of the first gas sensor, generating a second gas signal by means of the second gas sensor and detecting a defect in the battery arrangement if the first gas signal indicates the presence and / or a content of the gas component within the battery housing that exceeds a predetermined first content threshold value and the second gas signal indicates the absence and / or a content of the gas component outside the battery housing that falls below a predetermined second content threshold value.

[0034] The method according to the invention thus allows a defect in the battery assembly to be reliably detected, since the first gas signal can be verified for plausibility with the second gas signal. This allows, for example, an incorrect defect detection of the battery assembly to be detected if, for example, the gas component flows into the battery housing from outside the battery housing and, consequently, there is no defect in the battery assembly, such as one of the battery cells.

[0035] According to a preferred embodiment of the method according to the invention, the second gas signal is generated after a predetermined period of time has elapsed after the generation of the first gas signal. The method according to the invention further comprises detecting a defect in the battery assembly if the first gas signal indicates the presence and / or a content of the gas component within the battery housing that exceeds the predetermined first content threshold, and the second gas signal indicates the presence and / or a content of the gas component outside the battery housing that exceeds a predetermined third content threshold.

[0036] Therefore, if the temporal sequence of detection of the gas component is such that the gas component inside the battery housing is detected first and then the gas component outside the battery assembly is also detected, it can be assumed that the origin of the gas component is inside the battery housing and consequently a defect in the battery assembly can be detected.

[0037] In a further advantageous embodiment, the method according to the invention further comprises detecting a defect in the first gas sensor and / or the second gas sensor if only one of the two gas sensors generates a gas signal indicating the presence of a content of the gas component that is greater than the predetermined first content threshold value.

[0038] This can be exploited because, if the gas component is present, regardless of whether it is inside or outside the battery housing, both gas sensors should detect the gas component sooner or later due to a pressure equalization device in the battery assembly. However, if this is not the case, it can be determined that at least one of the two gas sensors is defective.

[0039] Further advantages and features of the present invention will become apparent to those skilled in the art by practicing the teachings described herein and viewing the accompanying single drawings in which:

[0040] Fig. 1 shows a schematic representation of a device according to the invention for a battery arrangement for a vehicle,

[0041] Fig. 2 shows a schematic representation of another device according to the invention for a battery arrangement for a vehicle, and

[0042] Fig. 3 shows a schematic representation of another device according to the invention for a battery arrangement for a vehicle,

[0043] Fig. 4 shows a schematic representation of a further device according to the invention for a battery arrangement for a vehicle, Fig. 5 shows a schematic representation of a further device according to the invention

[0044] Device for a battery arrangement for a vehicle,

[0045] Fig. 6 shows an exemplary flow diagram of a method according to the invention for detecting a defect in the battery arrangement of Fig. 4.

[0046] In the context of the present disclosure, a gas signal describes an electrical signal from a gas sensor that can qualitatively indicate the presence of one or more predetermined gas components, such as hydrogen, carbon dioxide, carbon monoxide and hydrocarbons, such as methane or ethane, and can quantitatively indicate the content of the one or more gas components.

[0047] Fig. 1 shows a battery assembly 100 according to the invention, which comprises a battery housing 110 configured to accommodate at least one battery cell 120, and a device 200 according to the invention. In Fig. 1, the at least one battery cell 120 is schematically illustrated as a block, although it is self-evident to those skilled in the art that the at least one battery cell can be arranged as known in the art.

[0048] The device 200 comprises a first gas sensor 210, which is configured to be sensitive to at least one gas component present within the battery housing 110 and to generate a first gas signal indicating the presence and / or content of the gas component within the battery housing 110. The first gas sensor 210 can thus indicate the content of the gas component within the battery housing 110 both qualitatively and quantitatively. Preferably, the first gas sensor 210 is configured to be sensitive to gas components generated during abnormal chemical reactions within the battery housing 110. In particular, the first gas sensor 210 can detect such an abnormal chemical reaction.For example, during a thermal runaway of the at least one battery cell 120, hydrogen, carbon dioxide, carbon monoxide, and hydrocarbons such as methane or ethane can be generated, which the first gas sensor 210 can detect. Depending on the progress of the reaction and thus the thermal runaway, the first gas sensor 210 can detect the characteristic gas concentrations of the respective gas component, which can be used to determine the condition of the battery or battery cells 120.

[0049] The device 200 further includes a second gas sensor 220 configured to be sensitive to the at least one gas component present outside the battery housing 110 and to generate a second gas signal indicating the presence and / or content of the gas component outside the battery housing 110. The second gas sensor 220 has a configuration similar to that of the first gas sensor 210 and can be sensitive to the same gas components as the first gas sensor 210.

[0050] The first gas sensor 210 has a sensor element 212 that is sensitive to the gas component. The second gas sensor 220 also has a sensor element 222 that is sensitive to the gas component. As shown in Fig. 1, the first gas sensor 210 can, for example, be inserted into the battery housing 110 such that the sensor element 212 of the first gas sensor 210 is at least partially located within the battery housing 110. In contrast, the second gas sensor 220 is arranged such that the second sensor element 222 of the second gas sensor 220 is at least partially located outside the battery housing 110.

[0051] The device 200 of Fig. 1 further comprises a control device 230, which is electrically connected to the first gas sensor 210 and the second gas sensor 220. The control device 230 can receive and process the first gas signal from the first gas sensor 210 and the second gas signal from the second gas sensor 220. In particular, the control device 230 can detect a defect in the battery assembly 100, in particular outgassing or thermal runaway of the at least one battery cell 120. If the first gas signal indicates the presence and / or a content of the gas component within the battery housing 110 that exceeds a predetermined first content threshold, but the second gas signal indicates an absence and / or a content of the gas component outside the battery housing 110 that falls below a predetermined second content threshold, a defect in the battery assembly 100 can be detected.In particular, it can be assumed that the gas component originates inside the battery housing 110, since the first gas sensor 210 detects the gas component, but the second gas sensor 220 does not (yet). In such a case, a warning can be issued to the driver of the vehicle.

[0052] Fig. 2 shows a schematic representation of another device 200 according to the invention for a battery arrangement 100 for a vehicle. The device 200 of Fig. 2 is similar to the device 200 of Fig. 1 and, in addition to the first gas sensor 210 and the second gas sensor 220, further comprises a device housing 240 in which the first gas sensor 210 and the second gas sensor 220 are at least partially arranged. The device housing 240 is designed to be attached to the battery housing 110 such that an opening 112 provided in the battery housing 110 is at least partially hermetically sealed by the device housing 240. According to the device 200 of Fig.2, the device housing 240 may have a device flange 242 that extends substantially outward from the device housing 240 and is supported on an outer wall of the battery housing 110, providing a connection option between the device housing 240 and the battery housing 110. For example, the device housing 240 may be welded or soldered to the battery housing 110 at the device flange 242.

[0053] Within the battery housing 240, a circuit board 244 is provided, to which both the first gas sensor 210 and the second gas sensor 220 are connected. The circuit board 244, in turn, is electrically connected to the control device 230 such that the first gas signals generated by the first gas sensor 210 and the second gas signals generated by the second gas sensor 220 can be received and processed by the control device 230.

[0054] The inventive device 200 of Fig. 2 thus represents a compact structural unit consisting of the device housing 240 and the gas sensors 210, 220 arranged at least partially therein, which can be relatively easily attached to the battery housing 100. In particular, the device housing 240 forms part of the battery housing 110 by being inserted into the opening 212 of the battery housing 110.

[0055] Fig. 3 shows a further schematic representation of a device 200 according to the invention for a battery arrangement 100 for a vehicle. The device 200 of Fig. 3 is similar to the device 200 of Fig. 2 and differs in that the device housing 240, in addition to a first housing region 246 in which the circuit board 244 is arranged, has a second housing region 248 which is separated from the first housing region 246. In particular, the second housing region 248 is arranged such that a flow path from the interior of the battery housing 110 to the exterior or into the surroundings of the battery housing 110 is enabled through the second housing region 248 (see exemplary flow path in Fig. 3, indicated by the arrow 10).

[0056] The second gas sensor 220 is arranged such that the second sensor element 222 of the second gas sensor 220 is at least partially arranged within the second housing region 248.

[0057] The device 200 of Fig. 3 also includes a pressure equalization device 250, which is attached to the device housing 240 and can establish a fluid connection between the interior of the battery housing 110 and the second housing region 248 for pressure equalization between the exterior of the battery housing 110 and the interior of the battery housing 110. Consequently, the fluid flow path 10 of Fig. 3 extends through the pressure equalization opening 250. It is self-evident to those skilled in the art that the direction of the fluid flow path 10 can also be in the opposite direction, namely from the exterior of the battery housing 110 through the second housing region 248 and the pressure equalization device 250 into the interior of the battery housing 210.

[0058] The device 200 of Fig. 3 further comprises a flow guide device 241, which extends at least partially into the interior of the battery housing 110 such that the fluid flowing from the battery housing 110 through the device 200, in particular through the second housing region 248, is at least partially guided past the first gas sensor 210. This ensures that in the event of a defect in the battery arrangement 100, in particular in the at least one battery cell 120, the gas generated thereby, containing the gas component sensitive to the gas sensor 210, flows at least partially past the sensor element 212 of the first gas sensor 210 and can be detected by the latter.

[0059] With the device 200 of Fig. 3, a compact unit consisting of device housing 200, first gas sensor 210, second gas sensor 220 and pressure compensation device 250 can thus be created, which can be attached to the battery housing 110 as a compact unit.

[0060] Fig. 4 shows a further schematic representation of another preferred embodiment of a device 200 according to the invention for a battery arrangement 100 for a vehicle. The device 200 of Fig. 4 is essentially the same as the device 200 of Fig. 3 and further comprises an emergency venting device 260 which, similar to the pressure equalization device 250, can enable a fluid connection between the interior of the battery housing 110 and the second housing region 248 and thus the exterior of the battery housing 110 in an emergency. The emergency venting device 260 can, for example, be a rupture disc, which can establish the aforementioned fluid connection when the pressure inside the battery housing 110 exceeds a predetermined pressure threshold, for example, approximately 50 mbar above the ambient pressure. In such a case, the rupture disc can rupture and thus completely vent the battery housing 110.With the device 200 of Fig. 4, a compact unit consisting of device housing 200, first gas sensor 210, second gas sensor 220, pressure compensation device 250 and emergency venting device 260 can thus be created, which can be attached to the battery housing 110 as a compact unit.

[0061] The emergency venting device 260 is particularly designed to increase the pressure equalization capacity of the pressure equalization device 250 when the predetermined pressure threshold value inside the battery housing 110 is exceeded. This means that the excess pressure inside the battery housing 110 can be equalized more quickly.

[0062] Fig. 5 shows yet another device 200 according to the invention for a battery arrangement 100 for a vehicle. The device 200 of Fig. 5 further comprises a third housing region 249, which is fluidly connected to the interior of the battery housing 110 and within which the sensor element 212 of the first gas sensor 210 can detect the gas component. The third housing region 249 is separated from the second housing region 248, within which the sensor element 222 of the second gas sensor 220 can detect the gas component, by means of a housing wall 243. The pressure equalization device 250 and the emergency venting device 260, which can establish a fluid connection between the third housing region 249 and the second housing region 248, can be arranged in the housing wall 243. In the embodiment of the device 200 of Fig. 5, the device housing 240 can also be fastened to the battery housing 110 via the device flange 240.

[0063] Fig. 6 shows an exemplary flow diagram of a method according to the invention for detecting a defect in the battery arrangement 100, for example by means of the device 200 of Fig. 4. However, it is self-evident to the person skilled in the art that the method according to the invention can also be carried out with the devices 200 according to the invention of Figs. 1 to 3 and Fig. 5.

[0064] The method of Fig. 6 starts at step 300 and then proceeds to step 320, where a first gas signal is generated by the first gas sensor 210. In a subsequent step 330, it is checked whether the first gas signal indicates the presence and / or a content of the gas component within the battery housing 110 that exceeds a predetermined first content threshold. If it is determined in step 320 that the gas signal indicates the presence and / or a content of the gas component within the battery housing 110 that does not exceed the predetermined first content threshold, the method proceeds to step 360, where a proper battery assembly 110 is determined before the method ends at step 370.

[0065] However, if it is determined in step 320 that the first gas signal indicates the presence and / or a content of the gas component within the battery housing 110 that exceeds the predetermined first content threshold, the method proceeds to step 330, at which a second gas signal is generated by the second gas sensor 220. The second gas signal is evaluated in step 340. If it is determined in step 340 that the second gas signal indicates the presence and / or a content of the gas component outside the battery housing 110 that exceeds a predetermined second content threshold, the method returns to step 360, at which no defective battery assembly 100 is determined before the method again ends at step 370.

[0066] In this case, it can be assumed that the gas component is present both outside and inside the battery housing 110.

[0067] In particular, the gas component was most likely first present outside the battery housing 110 and flowed, for example, into the interior of the battery housing 110 via the pressure equalization opening. The generation of the first and second gas signals in steps 310 and 330 preferably occurs simultaneously.

[0068] However, if it is determined in step 340 that the second gas signal indicates an absence and / or a content of the gas component outside the battery housing 110 that falls below the predetermined second content threshold, the method proceeds to step 350, where a defect in the battery assembly 100, for example, in the at least one battery cell 120, is detected before the method again ends in step 370. For example, a warning may be issued to the driver of the vehicle after or during step 350.

[0069] In particular, in step 340, it can be checked whether the gas component is also present outside the battery housing 110 at the same time. If this is the case, it can be assumed that the gas component has flowed into the battery housing 110 from outside the battery housing 110 and, consequently, the first gas sensor 210 also detects this gas component, and consequently, the first gas signal indicates the presence and / or a content of the gas component within the battery housing 110 that exceeds the predetermined first content threshold.

[0070] If, however, it is determined in step 340 that no or only a small amount of the gas component is (yet) detected outside the battery housing 110, it can be assumed that the gas component that was detected by the first gas sensor 210 inside the battery housing 110 was also generated inside the battery housing 110 and consequently there is most likely a defect in the battery arrangement 100, for example in the at least one battery cell 120, and can be detected accordingly.

[0071] Furthermore, it is according to the invention to provide a redundant gas measurement for the battery arrangement 100 by means of the two gas sensors 210, 220.

[0072] For example, the chronological order in which the first gas sensor 210 and the second gas sensor 220 detect the gas component can be analyzed. If the second gas sensor 220 detects the gas component before the first gas sensor 210, it can be assumed that the gas mixture including the gas component is flowing or has flowed into the battery housing 110 from the outside. However, if the first gas sensor 210 detects the gas component before the second gas sensor 220, it can be assumed that the gas mixture including the gas component is flowing or has flowed out from the interior of the battery housing 110. If only one of the two gas sensors 210, 220 detects the gas component within a predetermined period of time, it can be assumed that one of the two gas sensors 210, 220 is defective.In particular, the predetermined time period mentioned is so long that, if the two gas sensors 210, 220 function properly, both gas sensors 210, 220 would also have to detect the gas components, in particular due to the presence of the pressure compensation device 250.

[0073] In addition, the device 200 can be configured to detect the case in which the first gas sensor 210 detects the gas component much later than the second gas sensor 220. Rather, in a case in which the gas component flows from the outside into the interior of the battery housing 110, the first gas sensor 210 would have had to detect the gas component relatively shortly after the second gas sensor 220 has detected the gas component. However, if the first gas sensor 210 detects the gas component only after a predetermined period of time, such as in the range of 1 to 2 minutes, has elapsed, after the second gas sensor 220 has detected the gas component, a defect in the battery arrangement 100 can be concluded. In this case, the origin of the gas component detected by the first gas sensor 210 is likely inside the battery housing 110 and is not a gas component that flowed from the outside into the interior of the battery housing 110.

Claims

Patent claims 1. Device (200) for detecting a defect in a battery assembly (100), comprising a battery housing (110) and at least one battery cell (120) arranged in the battery housing (110), the device (200) comprising: a first gas sensor (210) configured to be sensitive to at least one gas component present inside the battery housing (110) and to generate a first gas signal indicating the presence and / or concentration of the gas component inside the battery housing (110), a second gas sensor (220) configured to be sensitive to the at least one gas component present outside the battery housing (110) and to generate a second gas signal indicating the presence and / or concentration of the gas component outside the battery housing (110), and a control device (230) connected to the first gas sensor (210) and the second gas sensor (220) and configured toto receive the first gas signal and second gas signal, wherein the control device (230) is further configured to detect a defect in the battery assembly (100) when the first gas signal indicates the presence and / or a concentration of the gas component inside the battery housing (110) that exceeds a predetermined first concentration threshold, and the second gas signal indicates the absence and / or a concentration of the gas component outside the battery housing (110) that falls below a predetermined second concentration threshold.

2. Device (200) according to claim 1, further comprising: a device housing (140) in which the first gas sensor (210) and second gas sensor (220) are at least partially arranged and which is designed to be attached to the battery housing (110) in such a way that an opening (112) provided in the battery housing (110) is at least partially sealed airtight by the device housing (240).

3. Device (200) according to claim 2, further comprising: a circuit board (244) arranged in the device housing (240), with which the first gas sensor (210) and the second gas sensor (220) are electrically connected, wherein the circuit board (244) is further electrically connected to the control device (230).

4. Device (200) according to one of claims 2 and 3, wherein the first gas sensor (210) extends sealingly from the interior of the device housing (240) at least partially into the interior of the battery housing (110), and / or wherein the second gas sensor (220) extends sealingly from the interior of the device housing (240) into the environment of the device housing (240) and the battery housing (110).

5. Device (200) according to one of claims 2 to 4, further comprising: a pressure equalization device (250) designed to at least partially equalize a pressure difference between the interior of the battery housing (110) and the exterior of the battery housing (110) and to vent or aerate the battery housing (110).

6. Device (200) according to claim 5, wherein the pressure equalization device (250) is arranged on the device housing (240) such that the fluid flowing out of or into the battery housing (110) through the pressure equalization device (250) at least partially flows past the second gas sensor (220).

7. Device (200) according to one of claims 5 and 6, further comprising: an emergency venting device (260) designed to vent the To vent the battery housing (110) when the pressure inside the battery housing (110) exceeds a predetermined pressure threshold.

8. Device (200) according to claim 7, wherein the emergency venting device (260) is arranged on the device housing (240) such that the fluid flowing out of the battery housing (110) through the emergency venting device (260) at least partially flows past the second gas sensor (220).

9. Device (200) according to one of claims 5 to 8, further comprising: a flow guide device (241) attached to the device housing (240) is attached and extends at least partially into the interior of the battery housing (110) in such a way that the fluid flowing out of the battery housing (110) through the pressure equalization device (250) is at least partially directed past the first gas sensor (220).

10. Device (200) according to one of claims 2 to 9, further comprising: a device housing (240) attached to the device housing Device flange (242) by means of which the device housing (240) can be attached to the battery housing (110).

11. Device (200) according to one of claims 2 to 10, wherein the device housing (240) has a housing area (246) which is fluidly connected to the interior of the battery housing (110), and a further housing area (248) which is fluidly connected to the exterior of the battery housing (110) and is separated from the housing area (246) by means of a housing wall (243).

12. Battery arrangement (100) for a vehicle, comprising: a battery housing (110) in which at least one battery cell (120) is arranged, and a device (200) according to one of the preceding claims.

13. Method for detecting a defect in a battery assembly (100) comprising a battery housing (110) and at least one component in the battery housing (110) a battery cell (120) arranged, comprising a first gas sensor (210) configured to be sensitive to at least one gas component present inside the battery housing (110) and to generate a first gas signal indicating the presence and / or concentration of the gas component inside the battery housing (110), and a second gas sensor (220) configured to be sensitive to the at least one gas component present outside the battery housing (110) and to generate a second gas signal indicating the presence and / or concentration of the gas component outside the battery housing (110), wherein the method comprises: Generating a first gas signal using the first gas sensor (210), Generating a second gas signal using the second gas sensor (220), and Detecting a defect in the battery assembly (100) when the first gas signal indicates the presence and / or concentration of the gas component inside the battery housing (110) exceeding a predetermined first concentration threshold, and the second gas signal indicates the absence and / or concentration of the gas component outside the battery housing (110) below a predetermined second concentration threshold.

14. The method of claim 13, wherein the second gas signal is generated after a predetermined time period following the generation of the first gas signal, the method further comprising: Detecting a defect in the battery assembly (100) when the first gas signal indicates the presence and / or a concentration of the gas component inside the battery housing (110) that exceeds the predetermined first concentration threshold, and the second gas signal indicates the presence and / or a concentration of the gas component outside the battery housing (110) that exceeds a predetermined third concentration threshold.

15. Method according to one of claims 13 and 14, further comprising: Detecting a defect in the first gas sensor (210) and / or second gas sensor (220) when only one of the two gas sensors (210, 220) generates a gas signal indicating the presence and / or concentration of the gas component that is greater than the predetermined first concentration threshold.

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