Battery fire extinguisher and its operating method

Abstract

A battery fire extinguishing device for preventing heat from spreading to the entire battery pack in the event of a fire occurring in some of the battery modules, the battery fire extinguishing device including: a plurality of extinguishing liquid storage units located respectively within a plurality of battery modules and configured to discharge extinguishing liquid when heated; a plurality of resistance units adjacent to each of the plurality of extinguishing liquid storage units; and a control circuit that monitors the voltage across both ends of the plurality of resistance units and increases the current flowing through each of the plurality of resistance units when the voltage becomes higher than a reference voltage.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] The present invention claims the benefit of priority based on Korean Patent Application No. 10-2022-0103000, filed on August 17, 2022, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference.

[0002] SUMMARY OF THE INVENTION The embodiments disclosed herein relate to a battery fire extinguishing device and method of operation. [Background technology]

[0003] Recently, research and development into secondary batteries has been actively conducted. Secondary batteries are batteries that can be charged and discharged, and include conventional Ni / Cd batteries, Ni / MH batteries, and the latest lithium-ion batteries. Among these, lithium-ion batteries have the advantage of having a much higher energy density than conventional Ni / Cd batteries, Ni / MH batteries, etc. Lithium-ion batteries can be manufactured in a compact and lightweight form, and are widely used as power sources for mobile devices. Recently, their use has expanded to include power sources for electric vehicles, drawing attention as a next-generation energy storage medium.

[0004] Recently, with the increasing use of large-capacity batteries, such as those used in electric vehicles, battery safety has become an issue. In particular, if a battery module were to explode or catch fire for some reason, it could lead to a major accident with serious human loss of life. Therefore, it has become important not only to monitor the battery status in real time, but also to minimize damage by quickly extinguishing a fire in a battery module. However, existing battery modules have few countermeasures against abnormal fires, and there is currently no technology to prevent thermal runaway by taking measures in neighboring battery modules if a fire breaks out in one battery module. Summary of the Invention [Problem to be solved by the invention]

[0005] One objective of the embodiments disclosed herein is to provide a battery fire extinguishing device and an operating method thereof that can suppress ignition using a fire-extinguishing liquid when a fire occurs in one of the battery modules that make up a battery pack, and prevent heat from spreading to other battery modules.

[0006] The technical problems of the embodiments disclosed in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0007] A battery fire extinguisher according to one embodiment includes a plurality of extinguishing liquid storage sections located respectively within a plurality of battery modules and configured to discharge extinguishing liquid when heated; a plurality of resistor sections adjacent to each of the plurality of extinguishing liquid storage sections; and a control circuit that monitors a voltage across both ends of the plurality of resistor sections and increases a current flowing through each of the plurality of resistor sections when the voltage becomes higher than a reference voltage.

[0008] In one embodiment of the battery fire extinguishing device, the plurality of resistors may be electrically connected in parallel to each other, and each resistor may include a heating pad that is broken by heating to open the connected circuit.

[0009] In one embodiment, the battery fire extinguisher may be configured such that when a heating pad included in at least one of the plurality of resistor units is destroyed, a voltage across both ends of the plurality of resistor units becomes higher than a reference voltage.

[0010] In one embodiment, the battery fire extinguisher may be configured such that when a current flowing through each of the plurality of resistors increases, the extinguishing liquid storage unit adjacent to each resistor is heated to discharge the extinguishing liquid.

[0011] In an embodiment of the battery fire extinguishing device, the fire extinguishing liquid may be composed of a material that prevents electrolyte gas in the battery module from contacting oxygen and lowers the temperature inside the battery module.

[0012] In one embodiment of the battery fire extinguisher, the control circuit includes a comparator for comparing a voltage across the plurality of resistor units with a reference voltage; a series resistor that can be connected in series with the plurality of resistor units; a power supply for supplying power to the plurality of resistor units and a circuit connected to the series resistor; and at least one switch for electrically connecting or disconnecting the plurality of resistor units and the series resistor, and when the voltage across the plurality of resistor units becomes higher than the reference voltage, the control circuit can increase the current flowing through each of the plurality of resistor units by disconnecting the electrical connection between the plurality of resistor units and the series resistor.

[0013] In the battery fire extinguisher according to an embodiment, the series resistor may have a resistance value greater than a total resistance value of the plurality of resistor units.

[0014] In the battery fire extinguisher according to an embodiment, the control circuit may further include a regulator that maintains the voltage supplied from the power supply unit at a constant level and supplies the voltage to the comparator.

[0015] A method of operating a battery fire extinguisher according to one embodiment includes monitoring a voltage across multiple resistors adjacent to each of multiple fire extinguishing liquid storage units located within multiple battery modules; and increasing a current flowing through each of the multiple resistors when the voltage becomes higher than a reference voltage.

[0016] In one embodiment of a method for operating a battery fire extinguisher, the step of increasing the current flowing through each of the plurality of resistor units may include the steps of: comparing a voltage across the plurality of resistor units with a reference voltage; and, when the voltage across the plurality of resistor units becomes higher than the reference voltage, controlling a switch circuit to cut off electrical connection between the plurality of resistor units and a series resistor having a resistance value greater than that of the plurality of resistor units.

[0017] The method for operating a battery fire extinguisher according to an embodiment may further include heating the plurality of resistors and the extinguishing liquid reservoir so that the extinguishing liquid is discharged from the extinguishing liquid reservoir. [Effects of the Invention]

[0018] According to the proposed battery fire extinguishing device, if a fire occurs in one of the battery modules that make up the battery pack, the device can automatically discharge fire extinguishing fluid to suppress the fire.

[0019] In addition, if a fire occurs in one of the battery modules, the fire extinguishing liquid is automatically discharged into all other battery modules, preventing the heat from spreading to the other battery modules.

[0020] In addition, various other effects may be provided that can be grasped directly or indirectly through this document. [Brief explanation of the drawings]

[0021] In order to more clearly describe the embodiments disclosed in this document or the technical solutions of the prior art, drawings necessary for describing the embodiments are briefly introduced below. The following drawings should be understood as being intended only to describe the embodiments of the present specification and not for the purpose of limitation. Also, for clarity of description, the depiction of some components in the drawings may be exaggerated or omitted.

[0022] [Figure 1]1 illustrates a structure of a battery module provided with a battery fire extinguishing device according to an embodiment. [Figure 2] 1 illustrates an equivalent circuit structure of a battery fire extinguishing device according to one embodiment. [Figure 3a] 1 illustrates an operation process of a battery fire extinguishing device according to an embodiment. [Figure 3b] 1 illustrates an operation process of a battery fire extinguishing device according to an embodiment. [Figure 3c] 1 illustrates an operation process of a battery fire extinguishing device according to an embodiment. [Figure 3d] 1 illustrates an operation process of a battery fire extinguishing device according to an embodiment. [Figure 4] 4 is a flowchart illustrating a method of operation of a battery fire extinguisher according to one embodiment. [Figure 5] 10 is a flowchart illustrating an operation method of a battery fire extinguisher according to still another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, the embodiments disclosed herein will be described in detail with reference to the accompanying drawings. When assigning reference numerals to components in each drawing, it should be noted that the same components are assigned the same reference numerals whenever possible, even if they appear in different drawings. Furthermore, when describing the embodiments disclosed herein, if a detailed description of related known structures or functions is deemed to hinder understanding of the embodiments disclosed herein, such detailed description will be omitted.

[0024] The terms used in this document have been selected as widely used and general terms as possible, taking into consideration their functions. However, these may differ depending on the intentions or practices of engineers in this field or the emergence of new technologies. In addition, in certain cases, the applicant may have arbitrarily selected terms, and in such cases, the meanings of these terms will be described in the explanation section of the specification. Therefore, it is clear that the terms used in this document should be interpreted based on the substantive meanings of the terms and the overall content of this document, rather than simply by their names.

[0025] Furthermore, the terms used in this document are merely used to describe specific embodiments and are not intended to limit the scope of other embodiments. A singular expression can include a plural expression unless clearly defined differently in the context. In this document, expressions such as "first" and "second" are used to distinguish components from each other and do not imply an order or hierarchy between the components.

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a battery fire extinguishing device and its operating method will now be described with reference to the drawings.

[0027] FIG. 1 shows the structure of a battery module equipped with a battery fire extinguishing device according to one embodiment.

[0028] Battery packs used as power sources for electronic devices such as electric vehicles consist of multiple battery modules, each of which may be composed of one or more battery cells. Battery cells are components that can be repeatedly charged and discharged and generate a potential difference through electrochemical reactions. Battery cells consist of a positive electrode, a negative electrode, a separator, and an electrolyte. A battery cell can catch fire if an internal short circuit occurs due to separator material, intrusion of metallic foreign matter, internal deformation, or separator damage, or if the battery cell overheats due to a control system abnormality. A fire in one battery cell can spread to other battery cells or the battery module in which that cell is located, and a fire in one battery module can spread to other battery modules and the entire battery pack.

[0029] Referring to FIG. 1, the battery pack is composed of a plurality of battery modules (M1, M2, M3, M4, ...), and one embodiment of the battery fire extinguisher includes a plurality of fire extinguishing liquid storage sections (P1, P2, P3, P4, ...) respectively located inside the plurality of battery modules (M1, M2, M3, M4, ...), a plurality of resistance sections (R1, R2, R3, R4, ...) adjacent to each of the plurality of fire extinguishing liquid storage sections (P1, P2, P3, P4, ...), and a control circuit 10 for controlling the current flowing through the plurality of resistance sections (R1, R2, R3, R4, ...).

[0030] The fire-extinguishing liquid reservoirs (P1, P2, P3, P4, ...) are located inside the battery modules (M1, M2, M3, M4, ...). According to one embodiment, each fire-extinguishing liquid reservoir may be configured as a pouch that ruptures when heated above a specific temperature, and the fire-extinguishing liquid discharged from the fire-extinguishing liquid reservoir may be configured as a substance that prevents electrolyte gas in the battery module from coming into contact with oxygen and lowers the temperature inside the battery module. Therefore, if a fire breaks out or the battery module is extremely heated, the fire-extinguishing liquid reservoir located within the module ruptures and discharges the fire-extinguishing liquid, thereby suppressing the fire.

[0031] The resistors (R1, R2, R3, R4, ...) are arranged adjacent to the fire extinguishing liquid storage units (P1, P2, P3, P4, ...), respectively, and may be attached to the surface of the fire extinguishing liquid storage unit (pouch). The resistors (R1, R2, R3, R4, ...) are electrically connected in parallel to each other and generate resistance heat when a current flows through the resistors. Each resistor includes a heating pad that breaks down when heated above a specific temperature, and breaking the heating pad opens the connected circuit.

[0032] Assuming that one of the battery modules (e.g., M1) among the multiple battery modules (M1, M2, M3, M4, ...) overheats above a certain temperature or catches fire, the extinguishing liquid storage unit (P1) will rupture, suppressing the ignition of that battery module (M1). At the same time, the other resistance units (R2, R3, R4, ...) connected in parallel to the resistance unit (R1) will heat up, rupturing the adjacent extinguishing liquid storage units (P2, P3, P4, ...), thereby suppressing or preventing the ignition of the other battery modules (M2, M3, M4, ...).

[0033] The control circuit 10 monitors the voltage across the resistors (R1, R2, R3, R4, ...) and when the voltage exceeds a reference voltage, it increases the current through each resistor, thereby inducing destruction of the extinguishing liquid reservoir adjacent to each resistor. The specific operation of the control circuit 10 will be described later.

[0034] Hereinafter, with reference to FIG. 2 and FIG. 3a to FIG. 3d, the operating principle of how a fire is suppressed in another battery module adjacent to a battery module where a fire has occurred will be described.

[0035] FIG. 2 shows an equivalent circuit structure of a battery fire extinguishing device according to one embodiment.

[0036] Referring to FIG. 2, the control circuit 10 of the battery fire extinguisher may include a comparator 110 for comparing the voltage across the resistor units (R1, R2, R3, ..., Rn) with a reference voltage (Vref), a series resistor (Rr), at least one switch 121, 122 for electrically connecting or disconnecting the resistor units and the series resistor, and a power supply unit 130 for supplying power to the circuit.

[0037] The comparator 110 compares the voltage (Vr) across the resistor units (R1, R2, R3, ..., Rn) with a reference voltage (Vref), and depending on the comparison result, opens and closes the switches 121 and 122 of the circuit to connect or disconnect the series resistor (Rr) and the resistor units (R1, R2, R3, ...).

[0038] In a normal state where the battery module is not in a fire or overheated, the plurality of resistors (R1, R2, R3, ..., Rn) are connected in parallel with each other, and the entire terminals of the resistors are connected in series with the series resistor (Rr). Here, the series resistor (Rr) is the total resistance (R Total ) has a larger resistance value than the resistance of the entire circuit. For example, each of the plurality of resistors (R1, R2, R3, ..., Rn) may have a resistance value of several to several tens of ohms, and the series resistor (Rr) may have a resistance value of several hundred kiloohms or more. Also, although the series resistor (Rr) is illustrated as a single resistor element in FIG. 2, it may have a configuration in which a plurality of resistors are connected in series. In such a normal state, according to the principle of voltage division, a large voltage is applied to the series resistor with a larger resistance value, and the resistance value (R Total +Rr) is so large that a small amount of current flows through the resistor sections (R1, R2, R3, ..., Rn).

[0039] 2, when there is no fire (i.e., no resistance in the resistor section is removed), the voltage (Vr) across the resistor section is lower than the reference voltage (Vref), so switch 121 remains open and switch 122 remains closed. Therefore, the resistor section (R1, R2, R3, ..., Rn) and the series resistor (Rr) are connected in series, and most of the voltage supplied by power supply 130 is applied to the series resistor (Rr).

[0040] Meanwhile, in an abnormal state where a battery module catches fire or is overheated above a certain temperature, for example, if a fire breaks out in the nth battery module among a plurality of battery modules, the fire-extinguishing liquid storage unit and the adjacent resistor (Rn) located within the battery module are overheated and destroyed. At this time, the fire-extinguishing liquid stored in the fire-extinguishing liquid storage unit can spread and automatically suppress the heat generation within the module, but if the fire-extinguishing liquid is not sufficient to completely suppress the heat generation, the heat may spread to other adjacent modules, resulting in a chain reaction of fires. According to the structure of the proposed embodiment, chain reaction of thermal runaway can be prevented in the following manner.

[0041] When a fire in a particular battery module destroys the heating pad included in the resistor unit (Rn), the circuit of that unit is opened. Referring to FIG. 2, when a part (Rn) of the multiple resistor units (R1, R2, R3, ..., Rn) connected in parallel is removed, the total resistance (R Total ) increases, which causes the voltage across the resistor (Vr) to also increase (voltage division principle).

[0042] In this case, too, the voltage (Vr) across the resistor section is much lower than the voltage across the series resistor (Rr) (due to the difference in resistance values), but when the voltage (Vr) across the resistor section becomes higher than the reference voltage (Vref), switch 121 is switched to a closed state and switch 122 is switched to an open state according to the comparison result of comparator 110. By operating the switches, the resistor section (R1, R2, R3, ...) and the series resistor (Rr) are electrically isolated, and most of the voltage supplied by power supply section 130 is applied to the resistor section (R1, R2, R3, ...).

[0043] As a result, the voltage across the resistors (R1, R2, R3, ...) increases significantly compared to normal conditions, and the current flowing through each resistor also increases significantly. As the current flowing through the resistors increases, the heat generated by the heating pads of each resistor also increases, causing the adjacent (or attached) fire extinguishing liquid reservoir to discharge fire extinguishing liquid above a specific temperature.

[0044] In other words, if a fire breaks out in one battery module, it will lead to destruction and open circuit of the resistor in that battery module, and the voltage and current applied to all ends of the resistor will increase significantly due to the switch control of comparator 110, which monitors the voltage change across all ends of the resistor. As a result, it will induce increased heat generation in the resistor (heating pad) in the battery module where the fire did not break out and destruction of the fire extinguishing liquid storage unit, thereby suppressing thermal runaway of the entire battery pack.

[0045] According to an embodiment, the control circuit 10 of the battery fire extinguisher may further include a regulator 140 for maintaining the voltage supplied from the power supply unit 130 at a constant level and supplying the voltage to the comparator 110 .

[0046] 3a to 3d illustrate the operation of a battery fire extinguishing device according to one embodiment.

[0047] 3a illustrates a plurality of battery modules (M1, M2, M3, M4, ...), a plurality of fire extinguishing liquid reservoirs (P1, P2, P3, P4, ...) respectively located within the battery modules, and a plurality of resistors (R1, R2, R3, R4, ...) adjacent to or attached to each of the fire extinguishing liquid reservoirs. As described above, the resistors (R1, R2, R3, R4, ...) are connected in parallel in the equivalent circuit.

[0048] As shown in Figure 3a, if a fire occurs inside a battery module (M1) due to an abnormality in the battery cell (e.g., an internal short circuit or an abnormality in the control system), as shown in Figure 3b, the extinguishing liquid storage section (P1) and resistor section (R1) in the module (M1) are destroyed by heat, and the extinguishing liquid stored in the extinguishing liquid storage section (P1) is discharged, thereby extinguishing the fire inside the battery module (M1) and suppressing heat generation.

[0049] Furthermore, as shown in Figure 3c, the opening of the circuit due to the breakdown of the resistor element (R1) increases the voltage applied to the other resistor elements (R2, R3, R4, ...) and the current flowing through each resistor element, causing the heating pads included in the resistor elements (R2, R3, R4, ...) to heat up rapidly.

[0050] As a result, as shown in Figure 3d, the extinguishing liquid storage sections (P2, P3, P4, ...) adjacent to or attached to the resistor sections (R2, R3, R4, ...) are also heated, and when the temperature reaches a certain level or above, the pouches burst and the extinguishing liquid is discharged.

[0051] Therefore, heat generation in the battery modules (M2, M3, M4, . . . ) other than the battery module (M1) where the fire occurred can be suppressed, and thermal runaway of the entire battery pack can be prevented.

[0052] 4 is a flowchart illustrating an operation method of a battery fire extinguisher according to an embodiment. The method according to the embodiment may be performed by the battery fire extinguisher described with reference to FIGS. 1 to 3, but is not limited thereto and may be performed by battery fire extinguishers having other structures or forms.

[0053] Referring to FIG. 4, in step S410, voltages across a plurality of resistors adjacent to a plurality of fire-extinguishing liquid storage units respectively located within a plurality of battery modules are monitored.

[0054] As described with reference to FIG. 1, the battery pack is composed of a plurality of battery modules (M1, M2, M3, M4, ...), a plurality of fire extinguishing liquid storage units (P1, P2, P3, P4, ...) can be located inside each battery module, and a plurality of resistor units (R1, R2, R, R4, ...) can be located adjacent to or attached to each fire extinguishing liquid storage unit.

[0055] According to one embodiment, the resistor units are electrically connected in parallel with each other, and each resistor unit may include a heating pad that is broken by heating to open the connected circuit. When a fire breaks out in one battery module, the fire extinguishing liquid storage unit inside the module is broken, causing the fire extinguishing liquid to be discharged and suppressing heat generation, and at the same time, the heating pad of the resistor unit is broken, opening the circuit and changing the voltage across all the terminals of the parallel-connected resistor units.

[0056] In step S420, when the voltage across the resistors (the remaining resistors excluding the destroyed resistor) becomes higher than the reference voltage, the current flowing through each resistor increases, heating the resistors and discharging the extinguishing liquid from the adjacent extinguishing liquid storage units. As a result, the extinguishing liquid suppresses heat generation in battery modules other than the battery module where the fire occurred, preventing thermal runaway of the entire battery pack.

[0057] FIG. 5 is a flowchart illustrating an operation method of a battery fire extinguishing device according to yet another embodiment.

[0058] 5, in step S510, voltages across both ends of a plurality of resistors adjacent to a plurality of fire-extinguishing liquid storage units located within a plurality of battery modules are monitored. Step S510 is similar to step S410 of FIG. 4, and therefore will not be described in detail.

[0059] In step S520, the voltage across the plurality of resistor units is compared with a reference voltage. Step S520 may be performed by the comparator 110 described with reference to FIG. 2, and when one of the plurality of resistor units connected in parallel is broken, the circuit is opened and the voltage across all of the plurality of resistor units increases.

[0060] In step S530, when the voltage across the multiple resistor units becomes higher than the reference voltage, the switch circuit is controlled to cut off the electrical connection between the multiple resistor units and a series resistor having a resistance value greater than that of the multiple resistor units, thereby increasing the current flowing through each of the multiple resistor units.

[0061] According to one embodiment, each of the plurality of resistor units may have a resistance value of several to several tens of ohms, and the series resistor may have a resistance value of several hundred kiloohms or more. Therefore, under normal conditions (i.e., when no fire occurs in any battery module), most of the voltage is applied to the series resistor, which has a much larger resistance value, and only a small amount of current flows through the plurality of resistor units.

[0062] On the other hand, in an abnormal state (when a fire breaks out in some battery modules and some resistors are destroyed), the voltage across the resistors becomes higher than the reference voltage, and the switch is opened or closed by the output signal from the comparator (110 in Figure 2), separating the series resistor from the resistors and increasing the current flowing through each of the resistors.

[0063] In step S540, the plurality of resistors and adjacent extinguishing liquid reservoirs are heated to discharge extinguishing liquid from the extinguishing liquid reservoirs. Specifically, as the series resistors and the resistors are electrically isolated, most of the voltage supplied from the power supply is applied to the resistors, which increases the current flowing through the resistors and heats the heating pad. As a result, the extinguishing liquid reservoirs adjacent to or attached to the resistors are ruptured by heating, discharging the extinguishing liquid and preventing heat diffusion to the battery module, which does not cause a fire.

[0064] The method for operating a battery fire extinguisher according to the embodiment may be implemented in the form of an application or in the form of program instructions that can be executed by various computer components, and may be recorded on a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, and the like, alone or in combination.

[0065] According to the above-described embodiments, if a fire occurs in one of the battery modules that make up the battery pack, the fire-extinguishing liquid can be automatically discharged to suppress the ignition, and the fire-extinguishing liquid can be automatically discharged into all other battery modules, thereby preventing heat from spreading to the other battery modules.

[0066] Therefore, it is possible to prevent the battery pack from exploding or escalating into a major fire due to an unexpected accident.

[0067] Although all components constituting the embodiments have been described above as being combined or operating in combination, the present invention is not necessarily limited to such an embodiment, and all components may be selectively combined and operate in one or more combinations within the scope of the intended purpose. Furthermore, unless otherwise specified, the terms "include," "comprise," "have," and the like used above mean that the relevant component may be inherent, and therefore should be interpreted as not excluding other components, but as including other components.

[0068] The above description is merely an illustrative example of the technical ideas disclosed in this document, and various modifications and variations are possible within the scope of those having ordinary knowledge in the technical field to which the embodiments disclosed in this document belong, without departing from the essential characteristics of the embodiments disclosed in this document.

[0069] Therefore, the embodiments disclosed in this document are intended to illustrate, not limit, the technical ideas disclosed in this document, and such embodiments do not limit the scope of the technical ideas disclosed in this document. The scope of protection of the technical ideas disclosed in this document should be interpreted according to the scope of the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of this document. [Explanation of symbols]

[0070] 10 Control circuit 110 Comparator 121, 122 switches 130 Power supply section 140 Regulator M1 Battery Module P1 Fire extinguishing liquid storage section R1, Rn resistance section Rr Series resistance RTotal Total resistance Vr voltage Vr voltage across both ends Vref Reference voltage

Claims

1. a plurality of fire-extinguishing fluid reservoirs respectively positioned within the plurality of battery modules and configured to discharge fire-extinguishing fluid upon heating; a plurality of resistors adjacent to each of the plurality of fire-extinguishing fluid reservoirs; and a control circuit that monitors a voltage across the plurality of resistor elements and increases a current through each of the plurality of resistor elements when the voltage exceeds a reference voltage.

2. 2. The battery fire extinguishing device according to claim 1, wherein the plurality of resistors are electrically connected in parallel with each other, and each resistor includes a heating pad that is broken by heating to open a connected circuit.

3. 3. The battery fire extinguishing device of claim 2, wherein when a heating pad included in at least one of the plurality of resistor elements is broken, a voltage across the plurality of resistor elements becomes higher than a reference voltage.

4. 4. The battery fire extinguishing device according to claim 3, wherein when the current flowing through each of the plurality of resistors increases, the fire extinguishing liquid storage unit adjacent to each resistor is heated to discharge the fire extinguishing liquid.

5. 5. The battery fire extinguishing device according to claim 4, wherein the fire extinguishing liquid is made of a material that prevents electrolyte gas in the battery module from coming into contact with oxygen and lowers the temperature inside the battery module.

6. The control circuit a comparator for comparing a voltage across the plurality of resistors to a reference voltage; a series resistor that can be connected in series with the plurality of resistor units; a power supply unit for supplying power to the plurality of resistor units and a circuit connected to the series resistors; and At least one switch is included for electrically connecting or disconnecting the plurality of resistor units and the series resistor; and 2. The battery fire extinguishing device of claim 1, wherein when the voltage across both ends of the plurality of resistor units becomes higher than the reference voltage, the electrical connection between the plurality of resistor units and the series resistor is cut off, thereby increasing the current flowing through each of the plurality of resistor units.

7. The battery fire extinguishing device according to claim 6 , wherein the series resistor has a resistance value greater than the total resistance value of the plurality of resistor sections.

8. 7. The battery fire extinguishing device according to claim 6, wherein the control circuit further comprises a regulator that maintains the voltage supplied from the power supply unit at a constant level and supplies the voltage to the comparator.

9. monitoring a voltage across a plurality of resistors adjacent to each of a plurality of fire-extinguishing fluid reservoirs located within the plurality of battery modules; and A method for operating a battery fire extinguisher, comprising: increasing a current flowing through each of the plurality of resistor units when the voltage becomes higher than a reference voltage.

10. Increasing the current flowing through each of the plurality of resistor units includes: comparing a voltage across the plurality of resistors to a reference voltage; 10. The method of claim 9, further comprising: controlling a switch circuit to cut off electrical connection between the plurality of resistor units and a series resistor having a resistance value greater than that of the plurality of resistor units when the voltage across both ends of the plurality of resistor units becomes higher than the reference voltage.

11. 11. The method of claim 10, further comprising heating the plurality of resistors and the extinguishing fluid reservoir so that extinguishing fluid is discharged from the extinguishing fluid reservoir.

Images