Description:FIELD OF THE INVENTION
Embodiments of the present disclosure relate to detecting and control thermal runaway events in energy storage devices, and more specifically, to detecting an onset of a thermal runaway, managing and controlling the spread of the thermal runaway reaction in energy storage devices.

BACKGROUND OF THE INVENTION
Generally, thermal runaway events occur when a large amount of heat is released due to increase in temperature, which results in increasing the heat and temperature and may often lead to destructive result. A well-known example of a thermal runaway event is excessive heating of Lithium-ion battery packs (also referred to as energy storage devices) in electric vehicles, electronic devices such as hand-held phones, and computing devices, where such events of thermal runaway in the battery packs have resulted in fires hazards, leading to pollution and destruction of the devices and vehicles. It is an object therefore of the present disclosure to detect occurrence of thermal runaways and mitigate the risks associated with such occurrences preventing hazardous situations.

SUMMARY OF THE INVENTION
Embodiments of the present disclosure relate to a method and system for addressing issues related to thermal runaways in energy storage devices (also referred to as battery packs or battery). In an embodiment a system for controlling a thermal runaway event is disclosed. In an embodiment, the system comprises a plurality of energy storage device, wherein the plurality of energy storage devices are coupled to form an energy storage unit. In an embodiment, the plurality of energy storage device may be coupled either in series or parallel. In an embodiment, each of the plurality of energy storage device has an anode and a cathode, wherein the anode and the cathode of each of the plurality of energy storage devices is connected to form a unit or a pack. In an embodiment, the anode and/or the cathode is coupled to a sensor unit. In an embodiment, the sensor unit is coupled to an actuator. In an embodiment, the actuator also comprises a Battery Management System (BMS), In an embodiment, the BMS may be built into the actuator as a single unit or may be separated and interfaced with the actuator. In an embodiment, the actuator and the BMS is placed proximate to the device.
In an embodiment, the sensor unit continuously monitors the heat generated by energy storage devices or the energy storage unit including the plurality of energy storage devices. In an embodiment, on determination of a temperature of any of the plurality of energy storage devices in the energy storage unit breaching a pre-defined threshold temperature, which is due to the heat generated within the energy storage device, the sensor unit from the energy storage device transmits a signal to the actuator. In an embodiment, on detection of the signal from the energy storage device the actuator along with the BMS isolates the energy storage device from the energy storage unit. In an embodiment, the signal is transmitted on detecting a change in a magnetic flux, which is caused to the internal heating within the energy storage device. Other embodiments are also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description is described with reference to the accompanying figures. Features, aspects, and advantages of the subject matter of the present disclosure will be better understood with regard to the following description and the accompanying drawings. The figures are intended to be illustrative, not limiting, and are generally described in context of the embodiments, and it should be understood that it is not intended to limit the scope of the disclosure to these particular embodiments. In the figures, the same numbers may be used throughout the drawings to reference features and components. In order that the present disclosure may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures. The figures together with detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages.
Figure 1 is an exemplary illustration an energy storage device (battery) with a sensor unit coupled to a BMS in accordance with embodiments of the present disclosure.
Figure 2A is an exemplary illustration of an energy storage unit (energy storage system) for controlling a thermal runaway event with a plurality of energy storage devices in accordance with embodiments of the present disclosure.
Figure 2B is an exemplary illustration of an energy storage unit where a heated energy storage device coupled to the energy storage unit is disengaged from the energy storage unit in accordance with embodiments of the present disclosure.
Figure 2C is an exemplary illustration of an energy storage unit where a heated energy storage device coupled to the energy storage unit is isolated from the energy storage unit in accordance with embodiments of the present disclosure.
Figure 3A is an exemplary illustration of an energy storage unit having a plurality of energy storage devices for controlling a thermal runaway event with a plurality of energy storage devices in accordance with embodiments of the present disclosure.
Figure 3B is an exemplary illustration of an energy storage unit where a heated energy storage device from a plurality of energy storage devices coupled in the energy storage unit is disengaged from the energy storage unit in accordance with embodiments of the present disclosure.
Figure 3C is an exemplary illustration of an energy storage unit where a heated energy storage device identified from amongst a plurality of energy storage devices coupled in the energy storage unit is isolated from the energy storage unit in accordance with embodiments of the present disclosure.
Figure 4 is an exemplary method for managing a thermal runaway in an energy storage system comprising a plurality of energy storage devices in accordance with embodiments of the present disclosure.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical elements. The figures as disclosed herein are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings are meant to only be provided as examples and/or implementations consistent with the description, and the description may not be limited to the examples and/or implementations provided in the drawings.

DETAILED DESCRIPTION
The following describes technical solutions in exemplary embodiments of the subject matter of the present disclosure with reference to the accompanying drawings. In this application as disclosed herein, "at least one" means one or more, and "a plurality of" means two or more. The term "and/or" describes an association relationship for describing associated objects and represents that three relationships may exist. For example, A and/or B may represent the following cases: Only A exists, both A and B exist, and only B exists, where A and B may be singular or plural. The character "/" usually indicates an "or" relationship between the associated objects. "At least one item (piece) of the following" or a similar expression thereof means any combination of the items, including any combination of singular items (piece) or plural items (pieces). For example, at least one item (piece) of a, b, or c may represent a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c each may be singular or plural.
It should be noted that in this application articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”. Throughout this specification defined above, unless the context requires otherwise the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps. The term “including” is used to mean “including but not limited to”. “Including” and “including but not limited to” are used interchangeably. In the structural formulae given herein and throughout the present disclosure, the following terms have been indicated meaning, unless specifically stated otherwise.
Unless otherwise defined, all terms used in the disclosure, including technical and scientific terms, have meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included for better understanding of the present disclosure. The term ‘about’ as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, is meant to encompass variations of ±10% or less, preferably ±5% or less, more preferably ±1% or less and still more preferably ±0.1% or less of and from the specified value, insofar such variations are appropriate to perform the present disclosure. It is to be understood that the value to which the modifier ‘about’ refers is itself also specifically, and preferably disclosed.
It should be noted that in this application, the term such as "example" or "for example" or “exemplary” is used to represent giving an example, an illustration, or descriptions. Any embodiment or design scheme described as an "example" or "for example" in this application should not be explained as being more preferable or having more advantages than another embodiment or design scheme. Exactly, use of the word such as "example" or "for example" is intended to present a related concept in only a specific manner.
It should be understood that in the embodiments of the present subject matter that "B corresponding to A" indicates that B is associated with A, and B can be determined based on A. However, it should be further understood that determining B based on A does not mean that B is determined based on only A. B may alternatively be determined based on A and/or other information.
In the embodiments of this application, "a plurality of" means two or more than two. Descriptions such as "first", "second" in the embodiments of this application are merely used for indicating and distinguishing between described objects, do not show a sequence, do not indicate a specific limitation on a quantity of devices in the embodiments of this application, and do not constitute any limitation on the embodiments of this application. In the present disclosure the word heat and temperature are synonymously used.
Exemplary embodiments of the present disclosure relate to a method and system for addressing issues related to thermal runaways in energy storage devices (hereinafter also referred to as battery packs or battery or cells). In an embodiment a system for controlling a thermal runaway event is disclosed. In an embodiment, the system includes a plurality of energy storage device, wherein the plurality of energy storage devices may be coupled to form an energy storage unit. In an embodiment, the plurality of energy storage device may be coupled either in series or parallel. In an embodiment, each of the plurality of energy storage device has an anode and a cathode, wherein the anode and the cathode of each of the plurality of energy storage devices may be connected to form the energy storage unit (also referred herein as an energy storage system or an energy storage pack.) In an embodiment, the anode and/or the cathode may be coupled to a sensor unit. In an embodiment, each of the plurality of energy storage devices, assuming that the anode is at one end of the energy storage device and the cathode at the opposite end of the anode, the anodes and cathodes of the plurality of energy storage devices may be coupled via a first connector at the anode and a second connector at the cathode. In an embodiment, if the anode and the cathode are at the same end, an interconnector may be used to connect each of the anodes and cathodes of the energy storage devices forming the energy storage unit.
In an embodiment, the sensor unit is coupled to an actuator. In an embodiment, the actuator may also include a Battery Management System (BMS), In an embodiment, the BMS may be built into the actuator as a single unit or may be separated and interfaced with the actuator. In an embodiment, the actuator and the BMS may be placed proximate to the energy storage device.
In an embodiment, the sensor unit continuously monitors the heat generated by energy storage devices and/or the energy storage unit including the plurality of energy storage devices. In an embodiment, on determination of a temperature of any of the plurality of energy storage devices in the energy storage unit breaching a pre-defined threshold temperature, which may be due to the heat generated within the energy storage device, the sensor unit of the energy storage device transmits a signal to the actuator. In an embodiment, on detection of the signal from the energy storage device the actuator along with the BMS isolates the energy storage device within the energy storage unit. In an embodiment, the signal may be transmitted on detecting a change in a magnetic flux, which may be caused to the internal heating within the energy storage device.
In an embodiment, coupling connectors, the sensor and the actuator preferably include an alloy. In an embodiment, the alloy preferably contains a magnetic material or a material which is sensitive to a magnetic flux, and the material undergoes a transformation. In an embodiment, during the transformation of the material a signal is generated and heat from the energy storage device may be deflected. In a preferred embodiment, the alloy may be a Half-Heusler alloy (?Ni?_50.4 ?Co?_3.7 ?Mn?_32.8 ?Sn?_13.1) wherein the alloy undergoes a transformation and reverse transformation in a temperature range covering the predefined threshold temperature. In an embodiment, the actuator may also comprise an alloy. It should be obvious to a person or ordinary skill in the art that other material and alloys that exhibit such property of transformation and reverse transformation may be used in the sensor unit and all such material fall within the scope of the present disclosure.
In an embodiment, the sensor may generate an electrical signal on identifying a change in a magnetic state. In an embodiment, on receiving the signal from the sensor unit at the actuator, the actuator, which may also include the BMS, isolates the energy storage device. In an exemplary embodiment, considering two energy storage devices in an energy storage unit, the BMS sends a signal to delink the first connector and/or the second connector that is coupling a first energy storage device from the second energy storage device. On successfully delinking the isolated energy storage device, the BMS is configured to release a substance on the isolated energy storage device, covering the isolated energy storage device with the substance, thereby completely isolating the affected energy storage device within the energy storage system.
In an embodiment, the sensor and/or the actuator may absorb heat generated in the energy storage device to undergo a transformation in order to deflect heat from the energy storage device. In an embodiment, in the event a thermal runaway is detected in any of the energy storage devices in the energy storage system, the sensor of the affected energy storage device, i.e., where the thermal runaway is about to occur, undergoes a transformation to generate the signal. In an embodiment, as previously mentioned the sensor unit may be placed anywhere within the energy storage device, but preferably closer to the anode or the cathode of the energy storage device. In an exemplary embodiment, the substance is preferably a polymeric phase change material, the polymeric phase change material on absorption of heat from the actuator melts and covers the energy storage device. It should be obvious that various other materials exhibiting such property may be used to achieve isolation of the energy storage device and all such material fall within the scope of the present disclosure.
In an exemplary embodiment, the actuator coupled to the first connector and/or the second connector. In an exemplary embodiment, the first connector and/or the second connector on absorption of heat from the identified energy storage device, undergoes a transformation and actuates in conjunction with the BMS releases of a substance on the identified energy storage device covering the device with the substance, thereby isolating the affected energy storage device from the energy storage system.
In an embodiment a method for controlling and managing a thermal runaway in a energy storage system is disclosed. In an exemplary embodiment, the energy storage system has a plurality of energy storage devices, and each of the plurality of energy storage devices has a sensor unit, as disclosed previously. Elements of the energy storage system/unit have been disclosed previously and will not be repeated. An exemplary embodiment includes determining a temperature of an energy storage device in the energy storage unit. In an exemplary embodiment, monitoring if the temperature of energy storage device breaches pre-defined threshold temperature. An exemplary embodiment includes transmitting a signal to indicate the onset of a thermal runaway in the energy storage device 100. An exemplary embodiment includes isolating the affected energy storage device by releasing a substance to surround the energy saving device.
An exemplary embodiment includes determining a temperature due to heat generated in an energy storage device by continuously monitoring heat generated in the energy storage device. An exemplary embodiment includes checking whether the temperature at the sensor of the energy storage device has breached a pre-defined threshold temperature. An exemplary embodiment includes transmitting a signal from the affected energy storage device to indicate the onset of a thermal runaway in the energy storage device, which includes detecting a change in a magnetic flux in the sensor of the energy storage device.
An exemplary embodiment includes isolating the affected energy storage device in the energy storage system. An exemplary embodiment includes delinking an electrical connection between the affected energy storage device and the other plurality of energy storage devices in the energy storage unit. An exemplary embodiment includes actuating a release mechanism to release a substance to isolate the affected energy saving device, and the substance has been disclosed previously.
An exemplary embodiment uses an alloy to detect and control a thermal runaway. In an exemplary embodiment, the alloy integrates sensing to achieve an active heat management, where sensing may be used to initiate other responses when the heat generated is beyond the threshold of the alloy to dissipate. In an exemplary embodiment, the alloy may be used to actuate a response mechanism to release a substance to reduce the thermal runaway heat and stop catastrophic or hazardous events. In a preferred exemplary embodiment, the alloy may be a ferromagnetic material or a Half-Heusler alloy. In an exemplary embodiment, a Nickel-Cobalt-Manganese-Tin (NiCoMnSn) or variants of the Nickel-Cobalt- Manganese-Indium (NiCoMnIn) may be used. In a preferred exemplary embodiment, the Half – Heusler alloy (?Ni?_50.4 ?Co?_3.7 ?Mn?_32.8 ?Sn?_13.1) may be preferrable to sense and actuate a release mechanism to release the substance isolating the affected energy storage device and control the thermal runaway event. In an exemplary embodiment, the alloy may be in austenitic form and on absorbing heat from the thermal runaway reaches a transformed form and deflects away heat from the environment. In an exemplary embodiment, the alloy undergoes transformation from an austenitic to martensitic form between 128C and 136C.
Reference is now made Figure 1 which is an exemplary illustration an energy storage device (battery) with a sensor unit coupled to a BMS in accordance with embodiments of the present disclosure. The exemplary illustration is a normal energy storage device with an anode and a cathode which when connected can power a connected device. Multiple variations of the energy storage device may be possible, and it should be obvious to a person skilled in the art that all such variations of the energy storage device fall within the scope of the present disclosure.
Energy storage device 100 (also referred to herein as battery or cell) anode end 110 at a first end and cathode end 120 at the other end, opposite to the first end. In an exemplary case, both anode and cathode may be located at the first end and be separated by a separator, and multiple such variations of the energy storage device with an anode and a cathode may be possible, and all such variation fall within the scope of the present disclosure. Energy storage device 100 has sensor unit 140. Sensor unit as illustrated is placed proximate to anode 110. However, it should also be obvious to a person of ordinary skill in the art that sensor unit 140 may be placed at any location within energy storage device 100, for example at the cathode or midway between the anode and the cathode and all such variation fall within the scope of the present disclosure.
Sensor unit 140 is coupled to actuator 130. Actuator 130 also includes a Battery Management System (BMS), wherein the BMS may be integrated into actuator or may be a separate unit placed outside actuator 130. In an exemplary case, when multiple energy storage devices are coupled to each other to form a energy storage unit, each energy storage device will be provided with an actuator and one of the actuators may be made to perform the role of a BMS. Aactuator 130 is preferably placed proximate to sensor unit 140 of energy storage device 100. Sensor unit 140 includes sensor 150, coil 160, and magnet 170. Coil 160 is placed on a first side of the sensor 150 and magnet 170 is placed on the other side of sensor 150, which is opposite to the first side. In an exemplary case, coil 160 may be placed on the top side of sensor 150 and magnet 170 may be placed on the bottom of coil 140. It should be obvious to a person skilled in the art that the position of the coil and the magnet may be interchanged or may be placed around the sensor at different locations and all such variations fall within the scope of the present disclosure.
Sensor Unit 140 is configured to detect and senses the onset of a thermal reaction, which may lead to a dangerous situation, and sensor unit 140 is either configured to alert a user or provided with a programmed response to actively cool the energy storage device and the energy storage system. Sensor unit 140 on detection and/or sensing the onset of a thermal reaction transmits a signal to actuator 130 and/or the BMS coupled with actuator 130. Sensor 150 in the sensor unit 140 and actuator 130 preferably contain a layer of the ferro magnetic shape alloy. It should be obvious to a person of ordinary skill in the art that other magnetic alloys may be used, and all such magnetic alloys fall within the scope of the present disclosure. As an exemplary case, ferro magnetic shape alloys were used in embodiments of the present disclosure. Coil 160 connected to sensor 150 is preferably made of a conducting material that does not melt at the higher temperatures due to heat generated within the energy storage device on the onset of a thermal runaway.
During the functioning of energy storage device 100, the temperature within energy storage device 100 is continuously monitored. When sensor 150 changes it’s shape to an increase in temperature due to heating within the energy storage device, a change in magnetic flux is detected at sensor unit 140. On detection of a change in the magnetic flux in sensor unit 140, sensor unit 140 triggers a signal, which is transmitted to actuator 130 and BMS. Change in magnetic flux is detected when the temperature within energy storage device 100 breaches a pre-defined threshold temperature. On breaching the pre-defined threshold temperature, energy storage device 100 undergoes a thermal runaway, and sensor unit 140 is configured to generate and transmit the generated signal to the actuator 130 (hereinafter reference to actuator will also mean an actuator and the BMS) by detecting a change in magnetic flux at sensor unit 140, which is caused due to the temperature within energy storge device 100 breaching the pre-defined threshold temperature.
Actuator 130 (along with the BMS) that is placed proximate and externally to energy storage device 100 as the energy storage device absorbs heat released. The signal from sensor unit 140 received by the BMS may actuate release of a substance that covers energy storage device 100, thereby protecting the energy storage unit comprising a plurality of energy storage devices and halt energy storage device 100 from undergoing any further thermal runaway. In an embodiment, a plurality energy storge devices 100 may be connected in parallel or in series to form an energy storage unit.
Reference is now made to Figure 2A, which is an exemplary illustration of an energy storage unit (energy storage system) for controlling a thermal runaway event with a plurality of energy storage devices in accordance with embodiments of the present disclosure. System 200A is an exemplary illustration for coupling two energy storage devices 100 in accordance with the embodiments of the present disclosure for efficiently controlling and/or efficiently managing a thermal runaway. Energy storage unit 200A contains first energy storage device 210 and second energy storage device 220. First energy storage device 210 and second energy storage device 220 may be coupled to each other either in series or in parallel. First energy storage device 210 and second energy storage device 220 are connected at the anode using first connector 212 and at the cathode using second connector 214. In a preferred embodiment, first connector 212 and second connector 214 includes a conducting material such that there is conductivity and power can be drawn from energy storage unit 200A.
First energy storage device 210 has first sensor unit 242 and second energy storage device 220 has second sensor 244 unit. First sensor unit 242 and second sensor unit 244 are similar to sensor unit 140 illustrated and discussed with respect to Figure 1. In the illustration, first energy storage device 210 and second energy storage device 220 are connected to actuator 230, and actuator has
BMS which may be internally built into the actuator or may be an external unit coupled with the actuator. BMS on detection of a thermal runaway by any of the energy storage device picks up the signal and is configured to provide instruction to actuator and isolate the affected energy storage device.
As illustrated first energy storge device 210 has sensor unit 242 and second energy storage device 220 has sensor unit 244 placed proximate to the anode end. It should be obvious as discussed previously the sensor unit within the energy storage device may be located anywhere within the energy storage device and all such combination of the energy storage device with the sensor unit fall within the scope of the present disclosure. In an exemplary case, sensor 242 of first energy storage device 210 and sensor unit 244 of second energy storage device 220 may be placed proximate to the cathode end or midway between the anode and the cathode.
First connector 212, Second connector 214, first sensor unit 242, and second sensor unit 244 preferably include a layer of an alloy of a conducting material. In an exemplary case, the alloy may be of ferromagnetic shape memory or or a Half-Heusler alloy. Substance 235 may be a high enthalpy polymeric phase change materials (PCM) that are generally placed above each of the plurality of energy storage devices and will be released on the affected energy storage device as determined by the BMS. First sensor unit 242 and second sensor unit 244 continuously monitor the temperature of their respective energy storage devices. When any of the energy storage device heats due to any anomaly, which may be likely to cause a thermal runaway reaction, the affected energy storage device is disconnects and isolated from the energy storage unit 200A. In a specific embodiment, the sensor unit may be configured to cool the energy storage device and after the energy storage device is cooled, the senor unit may monitor the energy storage device to ensure that the energy storage device is free of anomalies and then reconnect the energy storage device back to the energy storage unit.
Reference is now made to Figure 2B, which is an exemplary illustration of an energy storage unit where a heated energy storage device coupled to the energy storage unit is disengaged from the energy storage unit in accordance with embodiments of the present disclosure. Embodiment disclosed herein relate to a energy storage unit 200B for controlling and managing a thermal runaway, where the energy storage unit has a plurality of energy storage devices that are coupled to each other either in series or in parallel. Structure of the energy storage unit 200B and the energy storage devices 210, 220 have been discussed previously with respect to Figure 2A and will not be repeated again with respect to Figure 2B. The temperature of the first energy storage device 210 and the second energy storage device 220 are continuously monitored by first sensor unit 242 and second sensor unit 244. During the monitoring of the temperature, in an exemplary case, due to excess heat being generated within second energy storage device 210, the temperature of second energy storage device crosses or breaches a pre-defined threshold temperature. Sensor unit 242 of the second energy storage device, which includes a sensor, undergoes a transformation and/or a reverse transformation in a temperature range covering the predefined threshold temperature. Due to the transformation of the alloy in second sensor unit 244 when the temperature has breached the pre-defined threshold temperature, sensor unit 244 records a change in magnetic flux, and the change in magnetic flux results in a signal being transmitted from second sensor 244 to actuator 230 and BMS. The signal generated by second energy storage device 220 indicates the onset of the thermal runaway. In a preferred embodiment, the threshold temperature may be set to be between 128C and 136C for energy storage device 220. It should be obvious to a person of ordinary skill in the art that the temperature range may be customized as per the requirement and size of the energy storage device and all such variation fall within the scope of the present disclosure. In the exemplary case, the actuator 230 on receipt of signal from second energy storage device transmits a signal to the BMS to alert a user and/or actuate other safety systems or any other secondary management systems.
In the exemplary case, the actuator 230/BMS delinks first connector 212 coupling first energy storage device 210 with second energy storage device 220. In the exemplary case, first connector 212 connects the anode of first energy storage device with anode of second energy storage device 220. On detection of the thermal runaway, the actuator/BMS delinks first connector 212 from the affected energy storage device 220 on absorbing the heat from the overheating energy storage device 220 due the alloy layer undergoing a transformation and/or a reverse transformation to deflect heat from affected energy storage device 220. By delinking the energy storage device 220 from the energy storage unit 200B, the heat within energy storage device 220 is not transmitted to the energy storage device 210 or to first conductor 212 and/or second conductor 214 and the occurrence of a thermal runaway is controlled. The actuator 230 in conjunction with the BMS may actuate release of substance 235 to surround and cover the affected energy storage device 220 to reduce the heat in second energy storage device 220 and ensure that there is no thermal runaway reaction in the energy storage unit 200B.
Reference is now made to Figure 2C, which is an exemplary illustration of an energy storage unit where a heated energy storage device coupled to the energy storage unit is isolated from the energy storage unit in accordance with embodiments of the present disclosure. Elements and features of the energy system unit 200C that have been described previously with respect to Figure 2B are not repeated as the elements and the features with respect to the elements remain the same.
As illustrated in Figure 2B, the affected energy storage device 220 is identified to be the affected energy storage device and a signal will be transmitted to the actuator and the BMS for necessary action to be taken to isolate the affected energy storage device. On determination of a possible occurrence of a thermal runaway at second energy storage device, actuator 235 along with BMS actuates release of substance 235 to surround second energy storage device 220 by covering second energy storage device 220 with the substance. Preferably substance 235 may be a high enthalpy polymeric phase change materials (PCM) that are generally placed above each of the plurality of energy storage devices and will be released on the affected energy storage device as determined by the BMS. It should be obvious to a person of ordinary skill in the art that other material similar to substance disclosed above may be used and all such combination of substance fall within the scope of the present disclosure.
In an exemplary case, after sensor unit 244 of second energy storage device 220 sends a signal to the actuator 230. First connector 212 undergoes a transformation and/or a reverse transformation due to absorption of heat from second energy storage device 220 and transfers heat to the substance 235 that is placed proximate to second energy storage device 220. Substance 235 melts/dissolves and surrounds/encapsulates second energy storage device 220, thereby isolating second energy storage device from the energy storage unit 200B. By such an operation, thermal runaway in energy storage units containing energy storage devices may be effectively and efficiently controlled without causing much damage to the energy storage unit. Although the energy storage unit 200B as illustrated and explained with respect two energy storage devices coupled to each other, the energy storage unit may be replicated using multiple energy storage devices.
Reference is now made to Figure 3A, which is an exemplary illustration of an energy storage unit having a plurality of energy storage devices for controlling and managing a thermal runaway event with a plurality of energy storage devices in accordance with embodiments of the present disclosure. The illustration of exemplary Figure 3A is similar to that of Figure 2B except that exemplary Figure 3A covers a plurality of energy storage devices, whereas exemplary Figure 2A illustrates two energy storage devices for simplicity of understanding. As illustrated, a plurality of energy storage devices 310A – 301N may be connected either in series or in parallel to form energy storage unit 300A. Energy storage unit 300B may be used to provide electrical power to any device coupled with energy storage unit 300A.
Each of the plurality of energy storage devices 310A – 310N are coupled to each other within the energy storage unit by means of connectors 312A – 312N at the anode, and connectors 314A – 314N at cathode. As discussed previously, the illustration may be a specific embodiment depending on the type of cell used, and in case a different type of cell is used where the anode and cathode are on the same end of the energy storage device, an interconnector may be used to connect the plurality of energy storage devices 310A – 310N. Each of the plurality of energy storage devices 310A – 310N may be provided with an actuator or more than one actuator, each of the actuators having a BMS or coupled to a BMS.
As illustrated, plurality of energy storage devices 310A – 301N are coupled to actuators 330A, 330B, wherein actuators 330A, 330B in conjunction with the BMS is configured to detect an effected energy storage device, control material release mechanisms to release substance 335A-335N, depending on which energy storage device is affected thereby isolating the affected energy storage device. As illustrated in the exemplary case two actuators are shown, but it should be obvious to a person skilled in the art that the entire energy storage unit could have a single actuator coupled to a BMS or each of the plurality of energy storage devices in the energy storage unit could be coupled to an actuator and a BMS, and all such variations fall within the scope of the present disclosure and the function of the actuator and BMS remain the same as described above.
Substance 335A-335N is placed proximate to each of the plurality of energy storage devices 310A-310N such that the affected energy storage device when identified from the plurality of energy storage devices may be isolated. It should also be obvious to a person of ordinary skill in the art that multiple energy storage devices that may be affected by a thermal runaway, for example there could be two or more devices at a given instant experience a thermal runaway and all such affected energy storage devices may be isolated if required, all such variations fall within the scope of the present disclosure although the description explicitly is restricted to identifying and isolating a single energy storage device.
Each of the plurality of energy storage devices 310A – 310N is provided with sensors 342A-342N, which is continuously monitoring the health the respective energy storage device 310A-301N. As discussed previously, sensors 342A-342N may be placed either proximate to the anode or cathode or midway or at any other location within each of the energy storage devices. Sensors 342A-342N, connectors 312A-312N, 314A-314N and actuator 330A, 330B include a conducting alloy that undergoes a transformation and/or a reverse transformation in a temperature range covering the predefined threshold temperature.
Reference is now made to Figure 3B, which is an exemplary illustration of an energy storage unit where a heated energy storage device from a plurality of energy storage devices coupled in the energy storage unit is disengaged from the energy storage unit in accordance with embodiments of the present disclosure. As discussed previously, the exemplary case illustrates only one affected energy storage device, and it should be obvious to a person skilled in the art that there could be more than one affected device and embodiments of the present disclosure may be able to identify all the affected energy storage devices and isolated the affected energy storage devices. The illustration of exemplary Figure 3A is similar to that of Figure 2B except that exemplary Figure 3A covers a plurality of energy storage devices forming an energy storage unit, whereas exemplary Figure 2A illustrates two energy storage devices forming an energy storage device.
The temperature in each of the plurality of energy storage devices 310A-310N of the energy storage unit is continuously monitored by sensor units 342A-342N. If the temperature crosses or breaches a pre-defined threshold, for example in the illustration, considering energy storage device 310N has breached the threshold temperature, the alloy in sensor unit 342N of energy storage device 310N undergoes a transformation and/or a reverse transformation in a temperature range covering the predefined threshold temperature.
When such a situation is detected in energy storage device 310N, sensor unit 342N of energy storage device 310N generates a signal to actuator 330A or actuator 330B as a change in magnetic flux has been detected across sensor unit 342N, when the temperature of energy storage device 310N breaches the pre-defined threshold temperature. The signal indicates an onset of the thermal runaway, and the signal is transmitted to actuator 330A to which energy storage device 310N is couple to. In an exemplary case, it should be obvious to a person of ordinary skill in the art that if each of the energy storage devices is provided with an actuator, then the actuator coupled to the energy storage device receives the signal and passes the signal to the BMS, which will then provide the necessary course of corrective action to isolate the affected energy storage device.
In an exemplary embodiment, the threshold temperature may be between 40oC and 200oC in energy storage device 310N for sensor unit 342N generates a signal for transmission to actuator 330A or actuator 330B, that the energy storage device 310N is undergoing a thermal runaway, and the BMS is then provided with this signal from the respective actuator. In one embodiment, actuator 330A on receipt of signal transmits the signal to the BMS to alert the user and/or actuate other safety systems and/or secondary management systems to ensure that the affected energy storage device is isolated from the energy storage unit without the energy storage unit being affect as a whole. The exemplary temperature indicated here is only for purpose of illustration, but it should be appreciated that any heat that can result in a hazardous situation, covering a temperature from 40oC to about 200oC, wherein the heat can cause a fire, and any temperature that falls outside this range as well, falls within the scope of the present disclosure.
In an exemplary case as illustrated, actuator 330A delinks connector 312N to energy storage device 310N. In the exemplary case, connector 312N is delinked on absorbing heat from the overheating energy storage device 310N, where the alloy layer in connector 312N undergoes a transformation and/or a reverse transformation to deflect heat from energy storge device 310N. By delinking energy storge device 310N from the other plurality of energy storage devices in the energy storage unit, the heat from the affected energy storage device 310N is not transmitted to the adjacent energy storage devices and the thermal runaway is controlled and efficiently managed. In an exemplary case, first connector 312N may be still connected to energy storage device 310N to absorbs heat and deflect heat away from the affected energy storage device 310N. Actuator 330A may actuate release of substance 335N to surround and cover the affected energy storage device 310N to reduce the heat and ensure that there is no thermal runaway reaction in the energy storage unit.
Reference is now made to Figure 3C, which is an exemplary illustration of an energy storage unit where a heated energy storage device identified from amongst a plurality of energy storage devices coupled in the energy storage unit is isolated from the energy storage unit in accordance with embodiments of the present disclosure. In an exemplary case, Figure 3 illustrates controlling thermal runaway having multiple energy storage devices where a thermal runaway has occurred for a specific energy storage device 310N and the thermal runaway is controlled by releasing the substance on the energy storage device undergoing thermal runaway.
In the exemplary case, energy storage device 310N may be undergoing a thermal runaway, in which case, sensor unit 342N in energy storage device 310N generates a signal and sends the signal to actuator 330A. Actuator 330A in conjunction with the BMS actuates a release mechanism to release substance 335N onto energy storage device 310N, thereby isolating energy storage device 310N in the energy storage unit. Substance 335N surrounds energy storage device 310N and reduces the heat in the energy storage unit and the thermal runaway is effectively stopped.
In an exemplary case, after sensor unit 342N sends the signal to the actuator 330A, and if the actuator 330A along with the BMS does not have sufficient time to release the material, connector 312N undergoes transformation and/or a reverse transformation due to absorption of heat from energy storage device 310N transfers heat to substance 335N that may be placed proximate to energy storage device 310N. Substance 335N melts and surrounds energy storage device 310N and isolates the energy storage device 310N, thereby preventing any further thermal reaction. In the exemplary case, thermal runaway in the energy storage device is controlled and the affected energy storage device where the thermal runaway was identified is isolated without causing much damage to the energy storage unit.
Reference is now made to Figure 4, which is an exemplary method for managing a thermal runaway in an energy storage system comprising a plurality of energy storage devices in accordance with embodiments of the present disclosure. In step 410, a plurality of energy storage device may be coupled to form an energy storage unit. Each of the plurality of energy storage devices in the energy storage unit has a sensor unit to monitor the temperature within the energy storage device. In an exemplary case, whenever the energy storage device is heated due continuous use or any other parameter, the sensor unit continuously monitors the temperature produced by the heat generated. It should be obvious that other reactions within the energy storage device may also lead to a change in temperature in the energy storage device and all such variation fall within the scope of the present disclosure to protect the energy storage unit as a whole.
In step 420, the sensor unit is continuously monitoring the temperature energy storage device by monitoring the heat generated or other reactions that may influence the temperature. The temperature due to heat generated in the energy storage device is continuously monitoring to check whether the temperature of the energy storage device has breached the pre-defined threshold temperature and/or is reaching the pre-defined threshold temperature.
In step 430, wherein the sensor unit determines that the temperature of the energy storage device has breached the pre-defined threshold level and/or is close to the pre-defined temperature, the sensor unit, and particularly the sensor in the sensor unit undergoes transformation, which results in a change of magnetic flux in the sensor unit and the sensor unit generates a signal, which is then transmitted to an actuator including the BMS. Transmitting the signal indicate the onset of a thermal runaway in the energy storage device and is specifically addressed to prevent any hazardous situation from arising in the energy storage unit and/or a device or system that has such an energy storage unit.
In step 440, the actuator may be configured to absorb the heat from the energy storage device and release a substance to cover the energy storage device, thereby isolating the energy storage device. The BMS coupled to the actuator delinks an electrical connection between a plurality of energy storage devices and the affected energy storage device.
In an exemplary case, the energy storage unit use energy storage devices primarily of two geometries: 1) cylindrical and 2) pouch cells. It should be obvious to a person skilled in the art that other geometries may be possible, and all such geometries fall within the scope of the present disclosure. The energy storage units may be designed incorporating the above disclosed systems to ensure there is no delay in controlling thermal runaway. The system as disclosed herein to control thermal runaway event is easier to integrate with existing battery packs as compared to changing internal battery chemistry or construction of the battery packs.
Although the present disclosure has been described with reference to several preferred embodiments, it should be understood that the present disclosure is not limited to the preferred embodiments disclosed here. Embodiments of the present disclosure are intended to cover various modifications and equivalent arrangements within the spirit and scope of the appended claims. Although the foregoing disclosure has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practised within the scope of the appended claims. Examples of the present disclosure have been described in language specific to structural features and/or methods. It should be noted that there are many alternative ways of implementing both the process and apparatus of the present invention. Accordingly, embodiments of the present disclosure are to be considered illustrative and not restrictive, and the invention is not to be limited to the details given herein but may be modified within the scope and equivalents of the appended claims. It should be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed and explained as examples of the present disclosure. , Claims:We Claim:
1. An energy storage device 100, the energy storage device comprising:
- an anode 110 and a cathode 120; and
- a sensor unit 140, the sensor unit 140 located within the energy storage device 100, and the sensor unit 140 configured to continuously monitor a temperature of the energy storage device 100.

2. The energy storage device as claimed in claim 1, wherein the sensor unit 140 comprises:
- a sensor 150, the sensor 150 coupled to a coil 160 on a first side and coupled to a magnet 170 on the second side, wherein in the sensor 140, the coil 160 and the magnet 170 form the sensor unit 140.

3. The energy storage device as claimed in claim 2, wherein the sensor unit 140 detects a change of magnetic flux in the sensor when the temperature breaches the pre-defined threshold temperature.

4. The energy storage device as claimed in claim 3, wherein the sensor unit 140 generates a signal on detecting a change in magnetic flux due a change in the magnetic state of the sensor 150.

5. The energy storage device as claimed in claim 4, wherein the signal is an electrical signal.

6. The energy storage device as claimed in claim 1, wherein the sensor unit 140 is coupled to an actuator 130, wherein the actuator 130 is placed proximate to the energy storage device 100.

7. The energy storage device as claimed in claim 6, wherein the sensor 150 and the actuator 130 comprises:
- at least one of an alloy and/or a conducting material.

8. The energy storage device as claimed in claim 7, wherein the alloy and/or the conducting material comprises:
- a Half-Heusler alloy, wherein the alloy undergoes a state transformation and/or a reverse transformation in a temperature range covering the predefined threshold temperature.

9. The energy storage device as claimed in claim 2, wherein the actuator 130 comprises a Battery Management System, wherein the BMS is included as a part of the actuator 130 or may be externally coupled to the actuator 130.

10. The energy storage device 100 as claimed in claim 4, wherein the sensor unit 140 transmits the signal to the actuator 130.

11. The energy storage device 100 as claimed in claim 6, wherein the BMS along with the actuator is configured to isolate the energy storage device 100 on receipt of the signal.

12. An energy storage unit 200, the energy storage unit comprising:
a plurality of energy storage device 100, the plurality of energy storage device 100 coupled either in series or parallel within the energy storage unit 200;
each of the plurality of energy storage device 100 in the energy storage unit 200 comprises:
- an anode 110 and a cathode 120; and
- a sensor unit 140, the sensor unit 140 located within the energy storage device 100, and the sensor unit 140 configured to continuously monitor a temperature of the energy storage device 100;
- the sensor unit 140 coupled to an actuator 130; and
on determination of a temperature of any of the plurality of energy storage device 100 breaching a pre-defined threshold temperature in the energy storage unit 200, the sensor unit 140 from the energy storage device transmits a signal to the actuator 130 and a BMS to isolate the energy storage device from the energy storage unit 200.

13. The energy storage unit as claimed in claim 12, wherein each of the plurality of energy storage devices in the energy storage unit is coupled at an anode by a first connector 212 and at a cathode by a second connector 214.

14. The energy storage unit as claimed in claim 13, wherein the first connector 212 and the second connector 214 comprise a conducting material and/or an alloy.

15. The energy storage unit as claimed in claims 12, wherein the sensor unit of each of the plurality of energy storage devices comprises:
- a sensor150, the sensor 150 coupled to a coil 160 on a first side and coupled to a magnet 170 on the second side, wherein in the sensor 140, the coil 160 and the magnet 170 form the sensor unit 140.

16. The energy storage unit as claimed in claim 15, wherein each of the plurality of sensor unit 140 is configured to detect a change of magnetic flux in the sensor 150 when the temperature breaches the pre-defined threshold temperature.

17. The energy storage unit as claimed in claim 16, wherein the sensor unit 140 of the energy storage device is configured to generate a signal on detecting a change in magnetic flux due, wherein a change in magnetic flux occurs due to a change in the magnetic state of the sensor 150.

18. The energy storage unit as claimed in claim 17, wherein the signal generate from the sensor unit is an electrical signal.

19. The energy storage unit as claimed in claim 12, wherein each of the plurality of sensor and the actuator 230 comprises:
- at least one of an alloy and/or a conducting material.

20. The energy storage unit as claimed in claim 19, wherein the alloy and/or the conducting material comprises:
- a Half-Heusler alloy, wherein the alloy undergoes a state transformation and/or a reverse transformation in a temperature range covering the predefined threshold temperature.

21. The energy storage unit as claimed in claim 12, wherein the actuator 230 comprises a Battery Management System, wherein the BMS is included as a part of the actuator 330 or may be externally coupled to the actuator 230.

22. The energy storage unit as claimed in claim 21, wherein the BMS along with the actuator 230 is configured to isolate the energy storage device on receipt of the signal.

23. The energy storage unit 200 as claimed in claim 22, wherein isolating an identified energy storage device 100 comprises:
- on receiving the signal from the sensor unit 240, the actuator 130 along with BMS is configured to delink a first connector 212 coupling a first device 210 with a second device 220.

24. The energy storage unit 200 as claimed in claim 22, wherein isolating the identified energy storage device 100 comprises:
- on receiving the signal from the sensor unit 240, the actuator 130 along with BMS is configured to release a substance 235 on the identified device 210 covering the energy storage device 210 with the substance, thereby isolating the energy storage device 210.
25. The energy storage system as claimed in claim 24, wherein substance 235 is a polymeric phase change material, the polymeric phase change material on absorption of heat from the actuator 130 melts and covers the energy storage device.

26. A method for controlling and managing a thermal runaway in an energy storage unit, wherein the energy storage unit comprises a plurality of energy storage devices, the method comprising:
- monitoring 410 a temperature due in each of the plurality of energy storage devices;
- determining 420 if the temperature of energy storage device breaches a pre-defined threshold temperature,
- transmitting 430 a signal to indicate onset of a thermal runaway in the energy storage device where the temperature of the energy storage device has breached the pre-defined threshold temperature; and
- isolating 440 the energy storage device by releasing a substance surrounding the energy saving device.
.
27. The method as claimed in claim 26, wherein determining a temperature comprises: continuously monitoring heat generated within the energy storage device and checking whether the temperature of the energy storage device breaches the pre-defined threshold temperature.

28. The method as claimed in claim 26, wherein transmitting a signal to indicate onset of a thermal runaway in the energy storage device comprises: detecting a change in a magnetic flux in the sensor of the sensor unit of the energy storage device.

29. The method as claimed in claim 26, wherein isolating the energy storage device comprises:
- delinking an electrical connection between an affected energy storage device amongst the plurality of energy storage devices; and
- actuating a release mechanism to release a substance to isolate the affected energy saving device.

30. The method as claimed in claim 29, wherein the substance is a polymeric phase change material, the polymeric phase change material on absorption of heat from the energy saving device the substance melts and covers the energy storage device.

31. The method as claimed in claim 29, wherein the sensor of the affected energy storage device on absorption of heat generated undergoes a transformation and/or a reverse transformation to deflect heat from the energy saving device.

Dated this 16th day of January 2024
Indian Institute of Science
By their Agent & Attorney

Dr. Eric W B Dias/Reg No IN/PA 1058
of Khaitan & Co