Method for determining thermal runaway of a battery assembly, control device, battery device diagnostic device and computer program, and battery device and vehicle

Abstract

The invention relates to a method for determining a thermal runaway of a battery assembly, a control device (160), a battery device diagnostic device (170) and a computer program, and a battery device (100) and a vehicle. The method of the invention comprises receiving a thermal conductivity signal from a thermal conductivity sensor (140), receiving a presence signal from a Pellistor sensor (150), identifying a thermal runaway of a battery assembly (120) when the received thermal conductivity signal indicates that the thermal conductivity of a gas mixture inside a battery housing (110) exceeds a predetermined thermal conductivity threshold value and the received presence signal indicates that a flammable gas component is present in the gas mixture inside the battery housing (110), and sending an error signal when a thermal runaway of the battery assembly (120) is determined, wherein the error signal characterizes the thermal runaway of the battery assembly (120).

Description

Technical Field

[0001] The present invention relates to a method for determining thermal runaway of a battery assembly, a control device, a battery device diagnostic device, and a computer program, as well as a battery device and a vehicle. Background Technology

[0002] Whether in stationary applications such as wind power generation equipment or mobile applications such as electric or hybrid vehicles, new battery systems are increasingly being used as rechargeable energy storage devices, such as lithium-ion batteries or nickel-metal hydride batteries. To ensure the safety and functionality of such battery systems, the battery cells must operate within a predetermined temperature range. On the one hand, battery cells generate heat during operation, which must be dissipated to prevent the battery cells from exceeding their critical operating temperature. On the other hand, at low temperatures, it may also be necessary to heat the battery cells to a minimum temperature. To maintain the predetermined temperature range, temperature regulation of the battery system is known, i.e., cooling or heating as needed.

[0003] Therefore, it is known to use fluids, such as liquids like alcohols (e.g., propane-1,2,3-triol, glycerol), oils, or water, or mixtures of liquids, as temperature regulating media in the temperature regulating medium circuit to regulate the temperature of the battery system as needed. When the temperature regulating medium circuit in the battery system is damaged, such as in the event of a leak, the water-containing temperature regulating medium may be released. If the battery system casing is not hermetically sealed, moisture can continuously enter the battery system, for example, through an vent valve in the form of water vapor. Since the temperature of the temperature regulating medium is significantly lower than the temperature inside the casing when cooling the battery system, condensation may form inside the battery casing.

[0004] However, like all electrical, electronic, or information technology devices, such battery systems are highly sensitive to the presence of liquids such as water, as these liquids can cause or contribute to short circuits, corrosion, electrochemical migration, damage to insulation such as electrical insulation, and other harms.

[0005] However, the formation or presence of liquid within the battery casing can have various sources, such as the entry of moisture-containing air through unsealed seals, as described above. On the other hand, so-called thermal runaway (or thermal failure) of one of the battery cells within the casing can result from a reaction with hydrogen from the battery cell, or from a change in the composition of the gaseous mixture of the medium, leading to the formation of a liquid, such as water, inside the battery casing. Water can form, for example, when an organic electrolyte oxidizes with oxygen in the air. Furthermore, hydrogen can also be formed during the thermal decomposition of the electrolyte, which can react with oxygen in the air to form water.

[0006] Exemplary prior art includes US 2023 / 0349978A1, US 2015 / 0369784 A1, DE 102022 203664 B3, WO 2022 / 060845 A1 and CN 204154671 U. Summary of the Invention

[0007] The present invention is based at least in part on the task of early and reliable detection of thermal runaway of vehicle battery components.

[0008] This task is accomplished by the method according to independent claim 1, the control device according to claim 5, the battery device diagnostic device according to claim 7, the battery device according to claim 8, the vehicle according to claim 9, the computer program according to claim 10, and the computer-readable medium according to claim 11. Advantageous embodiments are given in the dependent claims.

[0009] The basic concept of this invention lies in reliably identifying thermal runaway of battery components for vehicles in a redundant manner using two different measurement methods. To this end, the invention detects the presence of hydrogen by measuring the thermal conductivity of the gas mixture inside the battery component, and simultaneously detects the presence of combustible gas components, such as hydrogen, in the gas mixture, thereby determining the risk of impending and already initiated thermal runaway. Thermal conductivity is determined by a thermal conductivity sensor, while the presence of combustible gas components in the gas mixture is detected by a Perlister sensor. Preferably, the Perlister sensor can operate at a significantly lower frequency to minimize aging and drift. It has been proven that Perlister sensors can drift or become poisoned during their operational lifespan. High temperatures can even exacerbate this effect.

[0010] Therefore, according to a first aspect of the present invention, a method for identifying thermal runaway of a battery assembly in a vehicle is disclosed. The battery assembly is located inside a battery casing. A thermal conductivity sensor is provided, configured to generate a thermal conductivity signal characterizing the thermal conductivity of a gas mixture inside the battery casing. Furthermore, a perlister sensor is provided, configured to generate a presence signal characterizing the presence of a combustible gas component in the gas mixture inside the battery casing. The method of the present invention includes: receiving a thermal conductivity signal from the thermal conductivity sensor, receiving a presence signal from the perlister sensor, identifying thermal runaway of the battery assembly when the received thermal conductivity signal indicates that the thermal conductivity of the gas mixture inside the battery casing exceeds a predetermined thermal conductivity threshold and the received presence signal indicates the presence of a combustible gas component in the gas mixture inside the battery casing, and sending an error signal when thermal runaway of the battery assembly is determined. The error signal characterizes thermal runaway of the battery assembly.

[0011] Preferably, the thermal conductivity signal is received from the thermal conductivity sensor at a first periodic interval, and the presence signal is received from the Perlist sensor at a second periodic interval, the second periodic interval being greater than the first periodic interval. Furthermore, it is further preferred that the first periodic interval is in the range of approximately 100 ms to approximately 10 seconds, while the second periodic interval is in the range of approximately 60 seconds to 5 minutes.

[0012] In this preferred embodiment, the Perlist sensor can operate significantly less frequently or at a lower frequency compared to a thermal conductivity sensor. This can result in the aging or drift of the Perlist sensor being kept as low as possible. Therefore, "pulsed" operation, i.e., non-continuous operation at longer intervals and at lower temperatures, is preferable for the Perlist sensor.

[0013] In another advantageous embodiment of the method of the invention, the thermal conductivity sensor has a heating device configured to heat the gas mixture and a temperature detection device configured to generate a temperature signal characterizing the temperature of the heating device and / or the temperature of the gas mixture surrounding the heating device. Generating the thermal conductivity signal includes sending a heating signal to the heating device, receiving a temperature signal from the temperature detection device, and generating the thermal conductivity signal based on the temperature signal. The heating signal sent to the heating device causes the heating device to operate at a predetermined electrical power.

[0014] According to another aspect of the invention, a control device is disclosed, which is configured to perform the steps of the method of the invention for identifying thermal runaway of a vehicle's battery assembly.

[0015] Preferably, the control device of the present invention includes a first control device portion for performing the step of receiving a thermal conductivity signal from a thermal conductivity sensor; a second control device portion for performing the step of receiving a presence signal from a perlister sensor; a third control device portion for performing the step of identifying thermal runaway of the battery assembly; and a fourth control device portion for performing the step of sending the error signal.

[0016] According to another aspect of the present invention, a battery device diagnostic apparatus for a vehicle is disclosed. The battery device diagnostic apparatus of the present invention includes a thermal conductivity sensor configured to be installed in a battery housing housing a battery module of a vehicle battery device; a perlister sensor configured to be installed in the battery housing housing a battery module of a vehicle battery device; and a control device of the present invention. The thermal conductivity sensor is configured to generate a thermal conductivity signal characterizing the thermal conductivity of a gas mixture inside the battery housing. The perlister sensor is configured to generate a presence signal characterizing the presence of a combustible gas component in the gas mixture inside the battery housing.

[0017] According to another aspect of the present invention, a battery device for a vehicle is disclosed, comprising a battery housing, a battery assembly disposed in the battery housing, and a battery device diagnostic device of the present invention.

[0018] According to another aspect of the present invention, a vehicle having a battery device of the present invention is disclosed.

[0019] According to another aspect of the present invention, a computer program is disclosed, comprising instructions that, when executed by a processing unit, cause the processing unit to perform the method of the present invention for identifying thermal runaway of a vehicle's battery assembly.

[0020] According to another aspect of the present invention, a computer-readable medium is disclosed having a computer program of the present invention stored thereon. Attached Figure Description

[0021] Other advantages and features of the invention will become apparent to those skilled in the art by practicing the teachings described herein in conjunction with the accompanying single drawing, wherein: Figure 1 A schematic diagram of a battery device for a vehicle according to the present invention is shown, and... Figure 2 A method for identification is shown. Figure 1 An exemplary flowchart of the method of the present invention for thermal runaway of battery components in a battery device. Detailed Implementation

[0022] Within the scope of this disclosure, the term "Perlister sensor" describes a gas sensor in the form of a resistance heater thermally isolated from the environment. This resistance heater heats a catalytically active layer thermally connected to the heater. The Perlister sensor is preferably constructed as a spiral of wound platinum wire embedded in ceramic beads, or as a micromechanical semiconductor film with a heater and a catalytic layer deposited on it.

[0023] Within the scope of this disclosure, the term "signal" describes raw data that has been converted into a form that can be transmitted through a selected transmission medium during data transmission. This can be done in an analog or digital manner, in which the data is first sampled and converted into discrete (typically binary encoded) values, and then transmitted through the medium as current pulses or voltages of varying levels. Furthermore, within the scope of this disclosure, the signal can be transmitted and / or received continuously. For example, the transmission and reception of digital signals occur at intervals of several milliseconds.

[0024] Figure 1 A battery device 100 according to the present invention is shown, having a battery housing 110 configured to house a battery assembly 120. As known in the prior art, the battery assembly 120 may have at least one battery cell. Figure 1 In this context, the battery assembly 120 is schematically represented as a single unit, and it will be self-evident to those skilled in the art that the battery assembly 120 and the battery cells—as is known in the prior art—can be arranged and connected to each other.

[0025] It should be mentioned here that the "interior of the battery housing 110" includes the free area surrounding the battery assembly 120. In particular, it is the fluid-filled, preferably air-filled area located inside the battery housing 110 surrounding the battery assembly 120.

[0026] The battery device 100 also includes a battery device diagnostic device 170, in Figure 1 In the illustrated embodiment, it includes a thermal conductivity sensor 140, a perlister sensor 150, and a control device 160.

[0027] The thermal conductivity sensor 140 is configured to generate a thermal conductivity signal that characterizes the thermal conductivity of the gas mixture inside the battery casing 110. The thermal conductivity sensor 140 can be a thermal conductivity sensor known in the art, based on the principle of thermal conductivity measurement. Here, by determining the thermal conductivity of the entire gas mixture, the concentration of one gas component in the gas mixture can be derived. In particular, for example, the hydrogen concentration in the gas mixture can be derived from this, because the thermal conductivity of hydrogen is significantly greater than that of many other gas components.

[0028] The measurement operation of this known thermal conductivity sensor 140 is essentially based on the constant operation of a heating device. Here, a predetermined electrical power is supplied to the gas mixture, and a predetermined thermal power is supplied to the heating device. The concentration of the gas component to be determined, such as hydrogen, can then be inferred from the heat carried away by the gas mixture. Here, a predetermined electrical power is supplied to the heating device, which, in the case of a known gas mixture without the component to be measured, will cause the gas mixture to reach a expected temperature. However, if the actual temperature of the gas mixture containing the gas component to be measured does not correspond to the expected temperature of the gas mixture without the gas component, the concentration of the gas component in the gas mixture can be inferred from the change in thermal conductivity of the gas mixture caused by the gas component. Specifically, the temperature difference between the heater and the temperature sensor can be determined.

[0029] Alternatively, the thermal conductivity sensor 140 is based on heating the gas mixture to a predetermined temperature using the heating device, wherein the electrical heating power required for this can be used as a measure of the thermal conductivity of the gas mixture inside the battery housing 110.

[0030] The Perlist sensor 150 is preferably a Perlist sensor known in the prior art and is configured to generate a presence signal indicating the presence of a combustible gas component, such as hydrogen, in the gas mixture inside the battery housing 110. This presence signal may be a binary signal and / or qualitatively indicate the approximate concentration of the combustible gas component in the gas mixture inside the battery housing 110.

[0031] It is explicitly stated here that the arrangement of the thermal conductivity sensor 140 and the Perlist sensor 150 can be arbitrarily chosen, and is therefore not limited to... Figure 1 The specific arrangement shown. For example, preferably, the thermal conductivity sensor 140 and the perlister sensor 150 are arranged on opposite sides of the battery assembly 120 within the battery housing 110.

[0032] The battery device diagnostic device 170 may also include a metal oxide semiconductor gas sensor (MOx-Sensor) configured to determine the concentration of a gaseous component, such as hydrogen.

[0033] The battery device diagnostic device 170 further includes a control device 160. The control device 160 may have a processor or a processing unit and a memory. Alternatively, the control device 160 may be the processor or the processing unit connected to the memory. The processor may be a central processing unit (CPU). The processor may also be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or another programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc.

[0034] The memory includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or portable read-only memory (2B CD-ROM). The memory is configured to store related program instructions and related data.

[0035] In the embodiment of Figure 1, the control device 160 has a first control device portion 162, a second control device portion 164, a third control device portion 166, a fourth control device portion 168, a fifth control device portion 167, and a sixth control device portion 169, which will be further described below in conjunction with... Figure 2 Further details will be provided. However, it should only be noted here that the fifth control unit section 167 and the sixth control unit section 169 are optional.

[0036] Figure 2 illustrates a method for identification. Figure 1 An exemplary flowchart of the method of the present invention for thermal runaway of the battery assembly 120 of the battery device 100.

[0037] Figure 2 The method begins at step 200 and then proceeds to step 210, in which the control device 160, particularly the first control device portion 162, receives a thermal conductivity signal from the thermal conductivity sensor 140. Preferably, the thermal conductivity sensor 140 is configured to generate and transmit a thermal conductivity signal at a first periodic interval, the first periodic interval being in the range of approximately 100 ms and 10 seconds.

[0038] In subsequent step 220, it is checked whether the thermal conductivity signal received in step 210 indicates that the thermal conductivity of the gas mixture inside the battery casing 110 exceeds a predetermined thermal conductivity threshold. If it is determined in step 220 that the thermal conductivity signal received in step 210 indicates that the thermal conductivity of the gas mixture inside the battery casing 110 does not exceed the predetermined thermal conductivity threshold, then the method proceeds to step 270 and ends.

[0039] However, if it is determined in step 220 that the thermal conductivity signal received in step 210 indicates that the thermal conductivity of the gas mixture inside the battery casing 110 exceeds the predetermined thermal conductivity threshold, the method proceeds to step 230, in which the control device 160, particularly the second control device portion 164, receives a presence signal from the Perlister sensor 150. Preferably, the Perlister sensor 150 is configured to generate and transmit a presence signal at a second periodic interval, which is greater than the first periodic interval. For example, the second periodic interval is in the range of approximately 60 seconds to 10 hours.

[0040] Alternatively, the first control device portion 162 and the second control device portion 164 may be constructed as a single control device portion, configured to receive both the thermal conductivity signal from the thermal conductivity sensor 140 and the presence signal from the perlist sensor 150.

[0041] In subsequent step 240, it is checked whether the presence signal received in step 230 indicates the presence of combustible gas components in the gas mixture inside the battery housing 110. If it is determined in step 240 that the presence signal received in step 230 does not indicate the presence of combustible gas components in the gas mixture inside the battery housing 110, the method proceeds to step 270 and ends.

[0042] However, if it is determined in step 240 that the presence signal received in step 230 indicates the presence of a combustible gas component in the gas mixture inside the battery housing 110, the method proceeds to step 250, in which the control device 160, particularly the third control device portion 166, determines that the battery assembly 120 is in thermal runaway. In the subsequent step 260, the control device 160, particularly the fourth control device portion 168, sends an error signal characterizing the thermal runaway of the battery assembly 120.

[0043] In another exemplary embodiment of the method of the present invention, if the received thermal conductivity signal indicates that the thermal conductivity of the gas mixture inside the battery housing 110 exceeds the predetermined thermal conductivity threshold, but the received presence signal does not indicate the presence of combustible gas components in the gas mixture inside the battery housing 110, a diagnostic signal may be sent. Alternatively or additionally, if the received thermal conductivity signal indicates that the thermal conductivity of the gas mixture inside the battery housing 110 does not exceed the predetermined thermal conductivity threshold, but the received presence signal indicates the presence of combustible gas components in the gas mixture inside the battery housing 110, the diagnostic signal may also be sent. The diagnostic signal may then indicate a malfunction of the thermal conductivity sensor 140 and / or the Perlist sensor 150.

[0044] Therefore, according to the present invention, a redundant system for reliably determining thermal runaway of the battery assembly 120 can be constructed, wherein the measurement principles of the two sensors are based on different physical principles, and preferably, the signals of each sensor are transmitted at different periodic intervals. This can, for example, reduce sensor aging and / or drift.

Claims

1. A method for detecting thermal runaway of a battery assembly (120) of a vehicle, wherein the battery assembly (120) is disposed within a battery housing (110), a thermal conductivity sensor (140) is provided, configured to generate a thermal conductivity signal characterizing the thermal conductivity of a gas mixture within the battery housing (110), and a perlister sensor (150) is provided, configured to generate a presence signal characterizing the presence of a combustible gas component in the gas mixture within the battery housing (110), the method comprising: - Receive thermal conductivity signal from the thermal conductivity sensor (140); - Receive presence signal from the Perlist sensor (150); - When the received thermal conductivity signal indicates that the thermal conductivity of the gas mixture inside the battery housing (110) exceeds a predetermined thermal conductivity threshold, and the received presence signal indicates that there are combustible gas components in the gas mixture inside the battery housing (110), thermal runaway of the battery assembly (120) is detected. - and when it is determined that thermal runaway has occurred in the battery assembly (120), an error signal is sent, the error signal indicating thermal runaway of the battery assembly (120).

2. According to the method described in 1, wherein, The thermal conductivity signal received from the thermal conductivity sensor (140) occurs at a first periodic interval, and the presence signal received from the Perlist sensor (150) occurs at a second periodic interval, the second periodic interval being greater than the first periodic interval.

3. According to the method described in 2, wherein, The first periodic interval is in the range of about 100 milliseconds to about 10 seconds, and the second periodic interval is in the range of about 60 seconds to 5 minutes.

4. According to any of the foregoing methods, wherein, The thermal conductivity sensor (140) includes a heating device for heating the gas mixture, and a temperature detection device configured to generate a temperature signal characterizing the temperature of the heating device and / or the gas mixture surrounding the heating device, wherein generating the thermal conductivity signal includes: - Send a heating signal to the heating device, the heating signal causing the heating device to operate at a predetermined electrical power; - Receive temperature signals from the temperature detection device; - and the thermal conductivity signal is generated based on the temperature signal.

5. A control device (160) configured to perform the steps according to any of the foregoing methods.

6. The control device (160) according to claim 5, comprising: - A first control device section (162) is used to perform the step of receiving a thermal conductivity signal from the thermal conductivity sensor (140); - The second control device part (164) is used to perform the step of receiving a presence signal from the Perlist sensor (150); - A third control unit (166) is used to perform the step of detecting thermal runaway of the battery assembly (120); - and - a fourth control unit (168) for performing the step of sending the error signal.

7. A battery diagnostic device (170) for a vehicle, comprising: - A thermal conductivity sensor (140) configured to be installed in a battery housing (110) of a vehicle battery assembly (100), the battery housing (110) housing a battery assembly (120), the thermal conductivity sensor (140) being configured to generate a thermal conductivity signal characterizing the thermal conductivity of a gas mixture within the battery housing (110); - A perlister sensor (150) configured to be installed in a battery housing (110) of a vehicle battery assembly (100), the battery housing housing a battery assembly (120), the perlister sensor being configured to generate a presence signal characterizing the presence of combustible gas components in a gas mixture within the battery housing (110); - and the control device (160) as described in 5 or 6.

8. A battery device (100) for a vehicle, comprising: - Battery casing (110); - A battery assembly (120) disposed within the battery housing (110); - and the battery device diagnostic device (170) according to 7.

9. A vehicle comprising a battery device (100) according to claim 8.

10. A computer program comprising instructions that, when executed by a processing unit, cause the processing unit to perform the method according to any one of 1 to 4.

11. A computer-readable medium having a computer program according to 10 stored thereon.

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