Battery system and electric vehicle including the same

Abstract

The invention relates to a battery system and an electric vehicle including the same. The battery system includes: a battery case; a battery cell in the battery case; an electronic vent valve at the battery housing and configured to be adjusted between an open position and a closed position via an electronic actuator; and a control unit configured to control the electronic exhaust valves to open synchronously or substantially simultaneously during thermal runaway.

Description

Technical Field

[0001] The present disclosure relates to battery systems and vehicles including the same that more safely handle thermal runaway of one or more of its battery cells. Background Art

[0002] Recently, vehicles for transporting goods and people have been developed that use electricity as a source of motion. Such electric vehicles are cars that can be propelled by an electric motor using energy stored in a rechargeable battery. Electric vehicles can be powered solely by batteries (e.g., battery electric vehicles (BEVs)) or can include a combination of an electric motor and, for example, a conventional internal combustion engine (e.g., plug-in hybrid electric vehicles (PHEVs)). BEVs and PHEVs use high-capacity rechargeable batteries designed to provide power for propulsion over a sustained period of time.

[0003] Generally speaking, a rechargeable (or secondary) battery cell includes an electrode assembly, which includes a positive electrode, a negative electrode, and a separator interposed between the electrodes. A solid or liquid electrolyte allows ions to move during charging and discharging of the battery cell. The electrode assembly is located in a shell, and electrode terminals located outside the shell can establish an electrically conductive connection with the electrodes. The shape of the shell can be, for example, cylindrical or rectangular. Summary of the Invention

[0004] The present disclosure may be limited by the following claims. The following description is subject to this limitation. Any disclosure outside the scope of the claims is intended for illustrative and comparative purposes only.

[0005] According to one aspect of the present disclosure, a battery system includes: a battery housing; a battery cell in the battery housing; an electronic exhaust valve at the battery housing and configured to be adjusted between an open position and a closed position via an electronic actuator; and a control unit configured to control the electronic exhaust valve to open synchronously or substantially simultaneously during thermal runaway.

[0006] The battery system may further include a sensor configured to detect thermal runaway inside the battery housing and output a sensor signal, wherein the control unit is configured to control the electronic exhaust valve in response to the sensor signal.

[0007] The sensor may include a pressure sensor configured to detect a pressure inside the battery housing, wherein the control unit is configured to control the electronic exhaust valve to open when the pressure exceeds a first value.

[0008] At least one of the electronic vent valves may include a mechanical backup vent element configured to open when a pressure inside the battery housing exceeds a second value.

[0009] The mechanical backup exhaust element may be located in the valve cover of the electronic exhaust valve.

[0010] The mechanical backup exhaust element may include a rupturable membrane.

[0011] The electronic actuator may include a solenoid for holding a valve cover of the electronic exhaust valve in a closed position when energized, wherein the valve cover defaults to an open position such that the valve cover moves to the open position when the solenoid is not energized.

[0012] The electric actuator may include an electric motor for driving the worm gear.

[0013] The battery system may further include a wire breakage detection mechanism for detecting whether a cable connection connecting the control unit and the one or more electronic exhaust valves is damaged.

[0014] Yet another aspect of the present disclosure relates to an electric vehicle including the battery system according to the present disclosure.

[0015] Further aspects of the present disclosure can be acquired from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Features will become apparent to those skilled in the art by describing the embodiments in detail with reference to the accompanying drawings, in which:

[0017] Figure 1 A schematic top view of a battery system according to one or more embodiments is shown.

[0018] Figure 2 Shown Figure 1 A cross-sectional view of an electronic exhaust valve of a battery system. DETAILED DESCRIPTION

[0019] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. Aspects of the embodiments and methods for implementing the same will be described with reference to the accompanying drawings. In the accompanying drawings, like reference numerals denote like elements, and redundant descriptions are omitted. However, the present disclosure may be embodied in a variety of different forms and should not be construed as being limited to the embodiments shown herein. Rather, these embodiments are provided as examples so that the present disclosure will be thorough and complete and will fully convey aspects of the present disclosure to those skilled in the art.

[0020] Therefore, processes, elements, and techniques that are not considered necessary for one of ordinary skill in the art to fully understand aspects of the present disclosure may not be described.In the drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity.

[0021] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. In addition, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure." In the following description of embodiments of the present disclosure, terms in the singular may include plural forms unless the context clearly indicates otherwise.

[0022] It will be understood that although the terms "first" and "second" are used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first element can be named as the second element, and similarly, the second element can be named as the first element without departing from the scope of this disclosure. As used herein, the term "and / or" includes any and all combinations of one or more related listed items. Expressions such as "at least one of" when following a list of elements modify the entire list of elements, rather than the individual elements of the list.

[0023] As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation, not as terms of degree, and are intended to take into account the inherent variations in measured or calculated values ​​that one of ordinary skill in the art would recognize. Additionally, if the term "substantially" is used in conjunction with a feature that can be expressed using a numerical value, the term "substantially" means a range of + / - 5% of that value centered around that value.

[0024] It will be further understood that the terms "include", "comprising", "including..." or "comprising..." specify attributes, regions, fixed numbers, steps, processes, elements, parts and combinations thereof, but do not exclude other attributes, regions, fixed numbers, steps, processes, elements, parts and combinations thereof.

[0025] It will also be understood that when a film, region or element is referred to as being “on” or “on” another film, region or element, it can be directly on the other film, region or element or intervening films, regions or elements may also be present.

[0026] Here, the terms "upper" and "lower" are defined relative to the z-axis. For example, the upper cover is located above the z-axis, while the lower cover is located below the z-axis. In the drawings, the sizes of elements may be exaggerated for clarity. For example, in the drawings, the size or thickness of each element may be arbitrarily illustrated for illustrative purposes, and thus the embodiments of the present disclosure should not be construed as limited thereto.

[0027] In the following description of the embodiments of the present disclosure, terms in the singular may include plural forms unless the context clearly indicates otherwise.

[0028] Any suitable hardware, firmware (e.g., an application specific integrated circuit), software, or a combination of software, firmware, and hardware may be utilized to implement the electronic or electrical devices and / or any other related devices or components according to the embodiments of the present disclosure described herein. In addition, the various components of these devices may be implemented on flexible printed circuit films, tape carrier packages (TCPs), printed circuit boards (PCBs), or formed on a substrate. The electrical connections or electrical interconnections described herein may be implemented, for example, by wires or conductive elements on a PCB or another circuit carrier. The conductive elements may include metallization, such as surface metallization and / or pins, and / or may include conductive polymers or ceramics. In addition, electrical energy may be transmitted via a wireless connection, for example, using electromagnetic radiation and / or optical transmission.

[0029] Furthermore, those skilled in the art will recognize that the functionality of various computing devices may be combined or integrated into a single computing device, or the functionality of a computing device may be distributed across one or more other computing devices without departing from the scope of the embodiments of the present disclosure.

[0030] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and / or this specification, and should not be interpreted in an idealized or overly formal sense, unless expressly defined as such herein.

[0031] In one or more embodiments, a battery module may be formed by connecting a plurality of battery cells in series or in parallel. The battery module may be formed by interconnecting electrode terminals of the plurality of battery cells depending on appropriate power levels to realize a high-power rechargeable battery.

[0032] Battery modules can be constructed in a block design or a modular design. In a block design, each battery cell is connected to a common current collector structure and a common battery management system, and the cells can be arranged in a housing. In a modular design, multiple battery cells are connected together to form a submodule, and several submodules are connected together to form a battery module. In automotive applications, the battery system generally includes multiple battery modules connected in series to provide the appropriate voltage.

[0033] A battery pack can be a collection of any number of (e.g., identical) battery modules or battery cells. The battery modules, each including a battery cell, can be configured in series, in parallel, or in a combination of series and parallel to deliver an appropriate voltage, capacity, and / or power density. The components of a battery pack can include individual battery modules and can include interconnects that provide electrical conductivity between the battery modules.

[0034] The battery system may also include a battery management system (BMS), which is any suitable electronic system configured to manage the rechargeable battery cells, battery modules, and battery packs, such as by protecting the battery from operating outside its safe operating area, monitoring the state of the battery, calculating auxiliary data, reporting the data, controlling the environment of the battery system, authenticating the battery system, and / or balancing the battery system. For example, the BMS may monitor the battery cell state as represented by voltage (e.g., the total voltage of the battery pack or battery module and / or the voltage of each battery cell), temperature (e.g., the average temperature of the battery pack or battery module, the coolant inlet temperature, the coolant output temperature, and / or the temperature of each battery cell), coolant flow (e.g., flow rate and / or cooling liquid pressure), and current.

[0035] In one or more embodiments, the BMS may calculate values ​​based on the above parameters such as minimum and maximum cell voltages, state of charge (SOC) or depth of discharge (DOD) indicating the charge level of the battery cell, state of health (SOH, which may be variously defined measures of the remaining capacity of the battery cell as a % of the original capacity), state of power (SOP, which may be the amount of charge available over a defined time interval given current power usage, temperature, and other conditions), state of safety (SOS), maximum charge current as charge current limit (CCL), maximum discharge current as discharge current limit (DCL), and the internal impedance of the cell (which determines the open circuit voltage).

[0036] The BMS can be centralized, with a single controller connected to the battery cells via multiple wires. In other examples, the BMS can also be distributed, where a BMS board is installed at each cell with only a single communication cable between the battery cell and the controller. In still other examples, the BMS can have a modular construction including several controllers that can handle a certain number of cells while communicating between the controllers. A centralized BMS can be the most economical, but can also be the least scalable and can include multiple wires. A distributed BMS can be the most expensive, but can be the simplest to install and can provide the cleanest components. A modular BMS can provide a compromise between the features and problems of the other two topologies.

[0037] The BMS can protect the battery pack from operating outside of its safe operating area. Operation outside the safe operating area can be indicated by overcurrent, overvoltage (during charging), overtemperature, undertemperature, overpressure, and ground fault or leakage current detection. The BMS can prevent the battery from operating outside of its safe operating parameters by including an internal switch (e.g., a relay or solid-state device) that opens if the battery is operated outside of its safe operating parameters, by requesting the device to which the battery is connected to reduce or even terminate use of the battery, and by actively controlling the environment (such as with the help of a heater, fan, air conditioner, or liquid cooling).

[0038] The exothermic decomposition of cell components can lead to so-called thermal runaway. In general, thermal runaway describes a process that is accelerated by an increased temperature and releases energy that further increases the temperature. Thermal runaway occurs when an increase in temperature changes conditions in a way that causes a further increase in temperature, often with destructive consequences. In rechargeable battery systems, thermal runaway is associated with a strongly exothermic reaction that is accelerated by an increase in temperature. In thermal runaway, the temperature of the battery cells rises relatively quickly and the stored energy is released relatively suddenly. Thermal runaway can potentially cause the battery cells to explode and catch fire, or can cause the battery cells to be damaged beyond repair.

[0039] If a battery cell is heated above a critical temperature (e.g., above approximately 150°C), it may transition into thermal runaway. Generally speaking, temperatures outside of the safe region, either on the low or high side, can cause irreversible damage to the battery cell, potentially triggering thermal runaway. Thermal runaway can also occur due to internal or external short circuits in the battery cell or poor battery maintenance. For example, overcharging or rapid charging can lead to thermal runaway.

[0040] During thermal runaway, a faulty battery cell can reach temperatures exceeding approximately 700°C. In addition, large amounts of hot gases can be ejected from the inside of the faulty battery cell through the exhaust openings of the cell housing into the battery pack. The main components of the exhaust gas can be H2, CO2, CO, electrolyte vapor, and other hydrocarbons. Therefore, the exhaust gas is flammable and potentially toxic. The exhaust gas can also cause an increase in gas pressure inside the battery pack. The high temperature can cause the process to propagate to adjacent cells and cause a fire in the battery pack, which is difficult to extinguish.

[0041] The venting concept of the battery can allow the exhaust gas flow discharged by one or more battery cells to expand into the battery housing and escape to the outside (e.g., to the environment of the battery housing) through the housing vent valve. A mechanical vent valve can be used, which can be mechanically opened by the pressure increase inside the battery housing caused by the exhaust gas flow. For example, such a mechanical vent valve may include a valve cover that is spring-loaded against the exhaust opening of the vent valve. If the pressure inside the battery housing increases, the force acting on the valve cover from the inside can exceed the spring loading force, so that the valve cover can be lifted from the exhaust opening and the exhaust gas flow can pass through the exhaust opening.

[0042] Generally speaking, the battery housing may include multiple mechanical vent valves to provide a sufficient cross-section to allow a sufficient flow rate of exhaust gas through the vent opening. Because the distribution of pressure inside the battery housing caused by thermal runaway may not be uniform, fewer than all mechanical vent valves may be opened simultaneously or by the same amount. If one of the mechanical vent valves opens, the pressure inside the battery housing may drop to a level too low for the other vent valves to open at all, which may reduce the likelihood of rapid exhaust gas discharge, which may lead to increased temperatures, accumulation of hot particles in critical areas, and overloading of one of the vent valves that has already been opened.

[0043] The present disclosure overcomes or reduces at least some of the shortcomings of the prior art to provide a battery system that more safely handles thermal runaway of one or more of its battery cells.

[0044] According to one aspect of the present disclosure, a battery system is provided. The battery system includes a plurality of battery cells. The battery cells are housed inside a battery housing of the battery system. The battery cells can be arranged or stacked along a stacking direction to form one or more single-cell stacks. The battery cells can be interconnected via electrical connection mechanisms (e.g., busbars) that contact the corresponding electrode terminals of the battery cells to form one or more battery modules / battery packs. The battery cells can be arranged to form one or more battery packs. In a battery pack, the battery cells can be electrically interconnected in series and / or in parallel, for example, as described above. A plurality of battery modules each including a battery cell can form a battery pack. The battery cell can be, for example, a prismatic or cylindrical cell.

[0045] Each battery cell may include an exhaust outlet on an exhaust side of the battery cell, which exhaust side may be a terminal side of the battery cell, where the electrode terminals of the battery cell are located. Each exhaust outlet may be adapted to allow exhaust gas to be discharged from the battery cell during thermal runaway of the corresponding battery cell. A vent element may be provided at the exhaust outlet, which vent element may open when a threshold pressure (e.g., a predefined pressure) is exceeded.

[0046] The battery system further includes at least two electronic exhaust valves, which can be arranged at the battery housing so that the exhaust air flow can leave the battery housing to the outside (for example, to the environment of the battery housing). The electronic exhaust valve can be located within the side wall of the battery housing or within another wall member of the battery housing. The electronic exhaust valve can be located in the same wall member or in different wall members. Each electronic exhaust valve is adapted to be moved or adjusted between an open position and a closed position. In the open position, the exhaust air flow can pass through the corresponding electronic exhaust valve and thus leave the battery housing. In the closed position, the corresponding electronic exhaust valve prevents the exhaust air flow from passing through the corresponding electronic exhaust valve, thereby preventing the exhaust air flow from leaving the battery housing. Each electronic exhaust valve can include a valve seat having an exhaust opening and a valve cover or valve plug for covering the exhaust opening in the closed position. In the open position, the valve cover can be moved away from the exhaust opening, thereby exposing the exhaust opening, so that the exhaust air flow can pass through the exhaust opening to the outside of the battery housing. In the closed position, the valve cover covers the corresponding exhaust opening, thereby preventing the exhaust air flow from leaving the battery housing.

[0047] The electronic exhaust valve may be movable or adjustable between an open position and a closed position via an electronic actuator controlled by a control unit. In one or more embodiments, the electronic exhaust valve is electronically adjustable or electronically triggered. In this sense, the electronic exhaust valve is an electronically actuated exhaust valve, or not just a mechanically actuated exhaust valve. For example, the control unit may generate an electronic signal and may send the electronic signal to an electronic actuator of the electronic exhaust valve, thereby opening the electronic exhaust valve. The electronic actuator may act on the valve cover to open or close the valve cover, and thus the electronic exhaust valve may be adjusted to an open position or a closed position, as explained in more detail below. The control unit may be a battery management system (BMS) of the battery system, or may form part of a battery management system (BMS) of the battery system.

[0048] According to the present disclosure, the at least two electronic vent valves (e.g., all electronic vent valves of a battery system) can open synchronously or substantially simultaneously. A control unit can be adapted to simultaneously open the at least two electronic vent valves in response to thermal runaway in one or more battery cells. The control unit can, for example, send the same electronic opening signal to the at least two electronic vent valves, causing the valves to open synchronously or substantially simultaneously. When the at least two electronic vent valves are opened synchronously or substantially simultaneously (e.g., opening all implemented electronic vent valves), the full cross-section of the vent valves can be reliably provided at a relatively early stage of a thermal runaway event. In one or more embodiments, the maximum possible volumetric flow rate of the exhaust gas flow through the electronic vent valves is ensured. Consequently, the temperature inside the battery housing can be maintained at a low level, and the exhaust gas flow and its particles (e.g., gas, dust, dirt, and hot particles) can be discharged quickly and reliably. Furthermore, compared to battery systems with mechanical vent valves, the maximum pressure inside the battery housing can be much lower because there is no need to overcome spring loading. Furthermore, during a thermal event, battery pack tightness (e.g., proper compression of the battery cells in the battery pack) can be reliably maintained (and not exceeded). Even if the pressure inside the battery case is unevenly distributed due to thermal runaway, all electronic vent valves can be opened simultaneously. Therefore, the battery system can more safely handle thermal runaway occurring in one or more of its battery cells.

[0049] According to one or more embodiments, the battery system further includes a sensor for detecting the occurrence of thermal runaway within the battery housing. The sensor may be located within the battery housing. The sensor may include one or more sensor elements for detecting the occurrence of thermal runaway. The sensor elements may be distributed within the battery housing. The sensor may be a pressure sensor. The sensor or its sensor elements may be adapted to detect the pressure within the battery housing. The sensor may output a sensor signal to a control unit to which the sensor is electrically connected. If thermal runaway occurs within the battery housing, the sensor signal may be output. The control unit may be adapted to control the electronic vent valves to open synchronously or substantially simultaneously in response to the sensor signal. For example, if the sensor is a pressure sensor, the sensor signal may be output when the pressure within the battery housing exceeds a threshold (e.g., a predetermined value). Furthermore, the control unit may determine whether the pressure detected by the sensor exceeds a certain value (e.g., a predetermined value). If the detected pressure exceeds a corresponding value, the control unit may control the electronic vent valves to open synchronously or substantially simultaneously. The corresponding value may be set to a relatively low value (e.g., below the pressure suitable for opening a typical mechanical vent valve) to ensure timely opening of the electronic vent valves. If at least one sensor element of the sensor detects a pressure exceeding a certain value (eg, a predetermined value), the control unit may open the electronic exhaust valve. In this way, the occurrence of thermal runaway may be reliably detected.

[0050] According to one or more embodiments, at least one of the electronic exhaust valves includes a mechanical backup exhaust element that is adapted to open if the pressure inside the battery housing exceeds a certain value (e.g., a predetermined value). The mechanical backup exhaust element can be adapted to open if the electronic exhaust valve fails. For example, the electronic exhaust valve can open as described above when a first pressure inside the battery housing is exceeded (e.g., a predetermined first pressure), while the mechanical backup exhaust element can open when a second pressure inside the battery housing is exceeded (e.g., a predetermined second pressure), wherein the second pressure can be higher than the first pressure. Therefore, during normal operation, the electronic exhaust valves can be opened synchronously or substantially simultaneously by the control unit as described above to ensure sufficient exhaust. If the system fails (e.g., because of a sensor or control unit failure), or if there is a power outage, the pressure will rise further until the second pressure is reached. The mechanical backup exhaust element can then open to allow emergency exhaust of the battery cell.

[0051] According to one or more embodiments, the mechanical backup exhaust element may be located in the valve cover of the electronic exhaust valve. In one or more embodiments, the mechanical backup exhaust element may include a rupturable membrane. As mentioned above, the electronic exhaust valve may include a valve seat having an exhaust opening and a valve cover covering the exhaust opening in the closed position. The mechanical backup exhaust element may be located within the valve cover. The mechanical backup exhaust element may cover the through-hole in the valve cover in the closed position. In the open position, the mechanical backup exhaust element may provide a passage to the through-hole so that the exhaust gas flow can pass through the through-hole and then pass through the electronic exhaust valve. For example, if the exhaust element includes a rupturable membrane, if the pressure inside the battery housing (e.g., a predetermined pressure) is exceeded, the rupturable membrane may rupture, allowing the exhaust gas flow to pass through. Therefore, the mechanical backup exhaust element can be constructed simply and reliably.

[0052] The electronic actuation of the electronic exhaust valve can be achieved by different technical solutions. According to one or more embodiments, the electronic actuator includes an electromagnetic element, which, if powered, is adapted to keep the valve cover of the exhaust valve in a closed position. In addition, the valve cover of the exhaust valve can be preloaded to an open position (for example, it can have a default position as the open position) so that if the electromagnetic element is not powered, the valve cover moves to the open position. In one or more embodiments, if the electronic actuator is powered (using, for example, a current provided by a control unit), the electronic exhaust valve remains in the closed position. If the electronic actuator is not powered (for example, if the control unit does not provide current), the electronic exhaust valve is in the open position. If a power loss occurs, the electronic exhaust valve can be snapped into the open position to ensure exhaust in the event of thermal runaway. Such electronic actuation can be relatively simple and reliable.

[0053] According to one or more embodiments, the electronic actuator may include an electric motor that drives a worm gear. The worm gear may be connected to a valve cover. The electronic actuator may include a worm gear and an electric motor, wherein, if thermal runaway occurs, the control unit may control the electric motor to drive the worm gear and the valve cover so that the electronic exhaust valve moves to an open position. Correspondingly, the control unit may control the electric motor to drive the worm gear and the valve cover so that the electronic exhaust valve moves to a closed position. Such electronic actuation may be relatively simple and reliable. In one or more other embodiments, the electronic actuator of at least one of the at least two electronic exhaust valves may include an electromagnetic element as described above, and the electronic actuator of another of the at least two electronic exhaust valves may include an electric motor that drives a worm gear as described above.

[0054] According to one or more embodiments, the battery system may further include a disconnection detection mechanism for detecting whether a cable connection or a wire connection connecting the control unit and one or more electronic exhaust valves is damaged. The control unit can be connected to the electronic exhaust valve via the wire connection as mentioned above. The disconnection detection mechanism can detect the integrity of the wire (e.g., a fault in the wire) and can output a corresponding signal. The control unit can receive the signal and can act accordingly. This can be used to achieve an appropriate automotive safety integrity level (ASIL).

[0055] The present disclosure also relates to an electric vehicle comprising a battery system (eg, a traction battery) according to the present disclosure.

[0056] Figure 1 and Figure 2 1 shows one or more embodiments of a battery system 100 according to the present disclosure. The battery system 100 includes a battery housing 10 and a plurality of battery cells 12 housed within the battery housing 10. Figure 1 In FIG, the battery cells 12 are arranged to form three battery groups 13, which may be separated by wall members 15 and may be interconnected in series via bus bars 16. The battery cells 12 may be arranged in different ways. On their top sides, the battery cells 12 may include exhaust outlets through which exhaust airflow may exit if thermal runaway occurs in the corresponding battery cell 12. Figure 1 In FIG, a thermal runaway event is shown as occurring in one of the battery cells 12 , resulting in an exhaust gas stream including gases and hot particulates being ejected from the affected battery cell 12 .

[0057] Reference Figure 1 , the battery system 100 further includes at least two electronic exhaust valves 20 (e.g., three electronic exhaust valves 20). The electronic exhaust valve 20 can be located at the side wall of the battery housing 10 and can be electrically connected to the control unit 30 (e.g., a battery management system) via the wire 17. The sensor 32 (e.g., a pressure sensor) can be located inside the battery housing 10 and can be adapted to detect the occurrence of thermal runaway inside the battery housing 10. The sensor 32 can continuously or periodically measure the pressure inside the battery housing, and the control unit 30 can determine whether the measured pressure exceeds a first value (e.g., a predetermined first value). If the measured pressure exceeds the first value, the control unit 30 sends a signal to the electronic exhaust valve 20 to open the electronic exhaust valve 20. Therefore, the exhaust air flow can leave the battery housing 10 via the electronic exhaust valve 20.

[0058] Reference Figure 1The electronic exhaust valve 20 can be adapted to be electronically actuated via a control unit 30 and move to an open position in response to a thermal runaway event being detected by a sensor 32, wherein the electronic exhaust valve 20 in the open position allows exhaust gas flow discharged by one or more battery cells 12 to pass through the electronic exhaust valve 20 and exit the battery housing 10.

[0059] Figure 2 One or more embodiments of one of the electronic exhaust valves 20 are depicted. Figure 2 The electronic exhaust valve 20 may include a valve seat 22 having an exhaust opening 23, a valve cover 24 covering the exhaust opening 23 in the closed position, and a valve cap 26. At the valve cap 26, the electronic actuator 21 may be connected to the valve cap 24 and may be adapted to move. In the closed position, the valve cap 24 may cover the exhaust opening 23 to seal the interior of the battery housing 10 from the outside. In order to provide an adequate seal, a first sealing element 27 (e.g., a sealing ring) may be provided on the side of the valve cap 24 that contacts the valve seat 22, and a second sealing element 28 may be provided on the side of the valve seat 22 that contacts the outer surface of the battery housing 10. The electronic exhaust valve 20 may further include a mechanical backup exhaust element 25 (e.g., a rupturable membrane), which is on the side of the valve cap 24 that faces and covers the exhaust opening 23.

[0060] According to the present disclosure, if thermal runaway occurs, the control unit 30 of the battery system 100 can be adapted to control the electronic exhaust valves 20 to open synchronously or substantially simultaneously. If the sensor 32 detects thermal runaway occurring within the battery housing 10 (e.g., based on detected overpressure), the control unit 30 can react by sending a control signal to the electronic exhaust valves 20 via the wiring 17 to simultaneously open all of the electronic exhaust valves 20. The synchronous or substantially simultaneous opening of all electronic exhaust valves 20 allows the entire cross-section of the exhaust openings 23 of all electronic exhaust valves 20 to be available relatively quickly and at a relatively early stage of a thermal runaway event. This ensures the maximum possible volume flow of exhaust gas through the electronic exhaust valves 20. Consequently, the temperature inside the battery housing can be maintained at a relatively low level, and the exhaust gas flow can be discharged quickly and reliably. Furthermore, compared to battery systems with mechanical exhaust valves, the maximum pressure inside the battery housing can be much lower because there is no spring load that must be overcome, and battery pack tightness can be reliably maintained during thermal events. Consequently, the battery system more safely handles thermal runaway occurring in one or more of its battery cells.

[0061] In one or more embodiments, the electronic actuator 21 may include an electromagnetic element that, when powered, holds the valve cover 24 of the electronic exhaust valve 20 in a closed position. The valve cover 24 may be preloaded to an open position such that, if the electromagnetic element is not powered, the valve cover 24 moves to the open position. In one or more embodiments, the electronic actuator 21 may include an electric motor that drives a worm gear. Other embodiments may provide for electrical actuation of the electronic exhaust valve 20.

[0062] If the electronic exhaust valve 20 fails (for example, due to a power outage), the battery system 100 can still ensure that the battery housing 10 is vented via the mechanical backup exhaust element 25 in the event of thermal runaway. The mechanical backup exhaust element 25 can be adapted to rupture if the pressure inside the battery housing 10 reaches or exceeds a second pressure (for example, a second predetermined pressure) that can be greater than the first pressure. The mechanical backup exhaust element 25 can expose a through hole extending through the valve cover 24 and can provide a path for the exhaust gas flow to pass through the electronic exhaust valve 20 to the outside. The battery housing 10 can be vented even if the valve cover 24 remains closed due to some failure.

[0063] The battery system 100 may further include a wire break detection mechanism for detecting whether the wire 17 connecting the control unit 30 and the electronic exhaust valve 20 is damaged. The wire break detection mechanism can detect the integrity of the wire and, for example, a wire failure, and can output a corresponding signal. The control unit 30 can receive the signal and take appropriate action. This can be used to achieve an appropriate Automotive Safety Integrity Level (ASIL).

[0064] Some reference numerals

[0065] 10 battery housing 12 battery cells

[0066] 13 battery pack 15 wall member

[0067] 16 busbars 17 wires

[0068] 20 Electronic exhaust valve 22 Valve seat

[0069] 23 exhaust opening 24 valve cover

[0070] 25 Mechanical backup exhaust element 26 Valve bonnet

[0071] 27 first sealing element 28 second sealing element

[0072] 30 control unit 32 sensor

Claims

1. A battery system comprising: Battery housing; a battery cell in the battery housing; an electronic vent valve at the battery housing and configured to be adjusted between an open position and a closed position via an electronic actuator, and The control unit is configured to control the electronic exhaust valves to open synchronously or substantially simultaneously during thermal runaway.

2. The battery system according to claim 1, wherein: At least one of the electronic vent valves includes a mechanical backup vent element configured to open when the pressure inside the battery housing exceeds a certain value.

3. The battery system according to claim 1 , further comprising a sensor configured to detect the thermal runaway inside the battery housing and output a sensor signal. in, The control unit is configured to control the electronic exhaust valve in response to the sensor signal.

4. The battery system according to claim 3, wherein: At least one of the electronic vent valves includes a mechanical backup vent element configured to open when the pressure inside the battery housing exceeds a certain value.

5. The battery system according to claim 3, wherein: The sensor includes a pressure sensor configured to detect pressure inside the battery housing, and Wherein, the control unit is configured to control the electronic exhaust valve to open when the pressure exceeds a first value.

6. The battery system according to claim 5, wherein: At least one of the electronic vent valves includes a mechanical backup vent element configured to open when the pressure inside the battery housing exceeds a second value.

7. The battery system according to claim 6, wherein: The mechanical backup exhaust element includes a rupturable membrane.

8. The battery system according to claim 6, wherein: The mechanical backup exhaust element is located in the valve cover of the electronic exhaust valve.

9. The battery system according to claim 8, wherein: The mechanical backup exhaust element includes a rupturable membrane.

10. The battery system according to claim 1, wherein: The electronic actuator includes an electromagnetic element for holding the valve cover of the electronic exhaust valve in the closed position when powered, and The valve cover is in the open position by default, so that when the electromagnetic element is not powered, the valve cover moves to the open position.

11. The battery system according to claim 1, wherein: The electric actuator includes an electric motor for driving a worm gear. 12 . The battery system according to claim 1 , further comprising a wire breakage detection mechanism for detecting whether a cable connection connecting the control unit and the one or more electronic exhaust valves is damaged.

13. An electric vehicle comprising a battery system according to any one of the preceding claims.

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