Thermal runaway diffusion prevention device of electric vehicle battery

Abstract

The thermal runaway diffusion prevention device for an electric vehicle battery of the present invention comprises: a battery pack (100) mounted on an electric vehicle, wherein multiple battery modules (120) are arranged on the left and right sides, an exhaust hole is provided on one side of an upper cover (150), a fire extinguishing water hole (131) is provided on the outer side of each lower cover (130), and a fire detection sensor (600) is installed for each module; a battery pack fire extinguishing device that connects fire extinguishing water automatic opening / closing nozzles (510) arranged in a fire extinguishing water supply pipe (500) branched from a cooling water circulation pipe (430) to supply cooling water from a cooling water tank (400) to the fire extinguishing water holes of each lower cover (130) to allow the cooling water to be used as fire extinguishing water; a connecting pipe (200) installed connected to the outer side of the fire extinguishing water hole of the battery module (120); and a gas guiding discharge pipe (230) connected to the connecting pipe (200) of the battery module (120) to guide and discharge fire and gas to the outside. It is characterized by being composed of: a fire extinguishing capsule mixing device (250) installed at the rear end of a gas induction discharge pipe (230) to mix fire extinguishing liquid when fire and gas pass through; a gas discharge port (260) installed at the rear of the fire extinguishing capsule mixing device (250) to be exposed from inside the vehicle body to the outside and then returned to its original position; and a control system (610) that receives a signal from a fire detection sensor (600) and controls the supply to the cooling water circulation pipe (430) and the fire extinguishing water supply pipe (500) and the operation of the circulation pump (410).

Description

Technology Field

[0001] The present invention relates to a device for preventing the spread of thermal runaway in an electric vehicle battery, and more specifically, to a device for preventing the spread of thermal runaway in an electric vehicle battery that, when thermal runaway occurs due to a fire in a battery installed in an electric vehicle, concentrates the supply of coolant provided in the vehicle or coolant introduced from the outside to the compartment containing the battery cell where the thermal runaway occurred, thereby preventing the thermal runaway from spreading to other compartments containing battery cells. Background Technology

[0003] Generally, the types of batteries installed and used in electric vehicles currently being produced and sold (hereinafter referred to as "electric vehicles") are classified into lithium-ion batteries, which have high energy density and long lifespan, and nickel-hydrogen batteries, which charge quickly and have good durability.

[0004] If the batteries of such electric vehicles are subjected to strong physical impact due to external collisions while driving, causing damage to the separator, or if the voltage rises due to overcharging during charging, causing swelling inside the battery and damaging the separator, thermal runaway due to overheating may occur, posing a risk of fire and explosion.

[0005] In addition, fires caused by thermal runaway in electric vehicle batteries are occurring not only when subjected to external physical impact or during charging, as described above, but also in electric vehicles driving on the road or parked for a long time due to battery overheating of unknown cause; however, the exact cause of this thermal runaway phenomenon in batteries has not yet been identified.

[0006] Furthermore, the reason it is difficult to extinguish fires in electric vehicles is that the battery pack is covered by upper and lower metal casings, preventing water and extinguishing agents from penetrating from the outside.

[0007] If we look at conventional methods used to extinguish fires in electric vehicles, liquid or gaseous extinguishing agents are sprayed onto the battery and vehicle body from the outside to prevent thermal runaway of the battery, or the fire is extinguished by covering it with a suffocation cover, or

[0008] A temporary water tank is installed to surround the vehicle body, and the tank is filled with fire extinguishing agent or water to immerse the battery of the burning electric vehicle in the agent or water, thereby suppressing the fire.

[0009] As mentioned above, fire suppression methods using suffocation covers or water tanks are methods currently implemented by the National Fire Agency as part of its accident response manual.

[0010] In addition, as a prior art related to electric vehicle fire suppression, there is the ‘method for suppressing fire in an electric vehicle using a rapid-installation water tank’ disclosed in ‘Patent Document 1’ of the prior art literature below, Korean Registered Patent Publication No. 10-2645759 (published on March 11, 2024).

[0011] The above 'Patent Document 1' is a method of transporting a water tank to the area where an electric vehicle fire occurred, installing the water tank to surround the electric vehicle that caught fire, and then filling the water tank with water to suppress the thermal runaway of the electric vehicle's battery.

[0012] However, this has the problem that the amount of water required to fill the tank is high, and since the water filled in this way is inefficient for completely extinguishing a fire caused by a battery runaway, it takes a considerably long time to suppress.

[0013] Another prior art is the ‘fire suppression system for electric vehicle charging stations’ disclosed in ‘Patent Document 2’, Korean Registered Patent Publication No. 10-2577099 (published September 12, 2023).

[0014] The above 'Patent Document 2' is configured to detect the presence of fire by installing a camera measuring device that captures general images and thermal images in a parking area equipped with an electric vehicle charger, and to prevent the external exposure of flames by having a flame-retardant film folded above the charging parking area unfold and cover the parked electric vehicle when a fire occurs, and to suppress the fire by spraying a fire extinguishing agent from an agent tank into the flame-retardant film.

[0015] Furthermore, when the advanced rod installed on the floor of the charging area penetrates the floor of the electric vehicle and enters the battery, the fire extinguishing liquid from the chemical tank is injected into the battery through the rod to extinguish the fire.

[0016] This ‘Patent Document 2’ is only capable of suppressing fires in electric vehicles parked in parking areas equipped with chargers, and has the problem of being difficult to deal with when a fire occurs in an electric vehicle parked in a general parking area or due to a collision while driving on the road.

[0017] In addition, if a fire breaks out in an electric vehicle in a place where fire trucks have difficulty entering, such as an underground parking lot of a building, and initial suppression is not effective, the fire can spread to numerous vehicles parked nearby, causing massive material damage.

[0018] For example, recently, an electric vehicle parked in the underground parking lot of an apartment complex in Incheon caught fire of unknown cause. As the battery experienced rapid thermal runaway and could not be suppressed in the initial stages, more than 140 of the hundreds of vehicles parked nearby were completely burned or suffered severe body damage due to the heat. Additionally, various pipes and electrical cables installed in the ceiling of the underground parking lot melted due to the high temperatures, resulting in water and power outages.

[0019] In addition, when a battery fire occurs in an electric vehicle, the fire becomes larger due to thermal runaway caused by overheating resulting from contact between the positive and negative electrodes as the separator is damaged, and toxic gases such as carbon monoxide, hydrofluoric acid, and toluene generated from the battery can cause casualties.

[0020] In particular, the risk is said to be significantly increased in enclosed underground parking lots, where the aforementioned toxic gases cannot escape easily, potentially making it difficult to enter the fire scene; however, existing fire suppression systems have not yet provided a method to reduce the toxic gases generated during such battery fires. Prior art literature

[0022] 'Method for extinguishing fire in electric vehicles using a rapid-installation water tank' of Korean Registered Patent Publication No. 10-2645759 (Published March 11, 2024) and 'Fire suppression system for electric vehicle charging stations' of Korean Registered Patent Publication No. 10-2577099 (Published September 12, 2023) The problem to be solved

[0023] The fire suppression method or fire suppression system of the aforementioned prior art has a problem in that it cannot quickly prevent the fire originating inside the battery pack from spreading to other areas, resulting in a long time required for fire suppression.

[0024] Accordingly, the present invention, developed to improve upon the problems of the aforementioned prior art, aims to provide an electric vehicle battery thermal runaway diffusion prevention device that suppresses thermal runaway early when it occurs in a battery mounted on a vehicle while parked, charging, or driving on the road, and prevents the thermal runaway from spreading to other places.

[0025] Another objective of the present invention is to prevent the spread of fire by guiding and discharging the flames and gases inside the battery pack that has caught fire to the outside of the vehicle body.

[0026] Another objective of the present invention is to reduce harmful gases generated from a battery that has caught fire, thereby reducing damage at the scene of the fire. means of solving the problem

[0028] To achieve the above objective, the present invention comprises: a battery pack mounted in an electric vehicle, wherein multiple battery modules covered by upper and lower covers are arranged on the left and right sides, an exhaust hole is provided on one side of the upper cover, a fire extinguishing water hole is provided in each lower cover, and a fire detection sensor is installed in each module; a battery pack fire extinguishing device that allows cooling water to be used as fire extinguishing water by connecting multiple automatic fire extinguishing water opening / closing nozzles arranged in a fire extinguishing water supply pipe branched from the cooling water circulation pipe of a cooling water tank to the fire extinguishing water holes of each lower cover; a connecting pipe installed on the outside of each exhaust hole of the upper cover; a gas induction discharge pipe connected to the connecting pipe to induce and discharge heat and gas generated by thermal runaway to the outside; and a fire extinguishing capsule mixing device installed at the rear end of the gas induction discharge pipe, which is filled with capsules containing fire extinguishing liquid to mix the fire extinguishing liquid when heat and gas pass through. The electric vehicle battery thermal runaway diffusion prevention device is characterized by comprising: a gas outlet installed at the rear of a fire extinguishing capsule mixing device, which is exposed from inside the vehicle body to the outside by means of movement and return and then returns to its original position; and a control system that receives a signal from a fire detection sensor and controls the operation of a first valve of the cooling water circulation pipe, a second valve of the fire extinguishing water supply pipe, and a circulation pump.

[0029] Here, each of the above-mentioned battery modules is installed on a lower cover such that multiple battery cells form a bundle, and a predetermined spacing is provided between each bundle. The two sides and the top surface of each bundled battery cell are covered to be isolated by using the spacing, and the separation wall pad is provided with a passage in the shape of an uneven surface, so that when thermal runaway occurs, the water blocking material is provided on a part of the side, and the water blocking material is dissolved and opened, thereby allowing water to be supplied through the passage.

[0030] In addition, the connecting pipe is equipped with a sealing blocker and a backflow prevention valve, and the fire water supply pipe is connected to an external pipe equipped with a one-touch socket, so that fire water can be supplied from the outside to the thermal runaway occurrence site through an external inlet hose connected to the one-touch socket with a one-touch plug. Effects of the invention

[0032] The present invention has the effect of suppressing the thermal runaway early and preventing it from spreading to other battery cell compartments by concentrating the supply of coolant from the vehicle or coolant from an external source to the compartment containing the battery cell where the thermal runaway occurred, in the event of a fire caused by battery thermal runaway during battery charging, parking, or driving.

[0033] In addition, it is effective in preventing the spread of fire and minimizing damage caused by toxic gases at the fire scene by exhausting flames and heat from the compartment containing the battery cell where thermal runaway has occurred to the outside of the vehicle body through the flammable gas exhaust pipe, and by effectively burning and expelling toxic gases to the outside. Brief explanation of the drawing

[0035] FIG. 1 is a side view showing the battery thermal runaway diffusion prevention device of the present invention mounted on an electric vehicle. FIG. 2a is a plan view showing the battery thermal runaway diffusion prevention device of the present invention mounted on an electric vehicle. FIG. 2b is a plan view showing the state in which gas is discharged through the gas outlet from the battery module where thermal runaway occurred in FIG. 2a. FIG. 3 is a side cross-sectional view showing the state in which firefighting water is injected into a battery module where thermal runaway has occurred and gas is discharged in the present invention. FIG. 4 is a perspective view showing the components of a battery pack separated in the present invention. FIG. 5 is an exploded perspective view of the battery module and the separator pad in the present invention. FIG. 6 is a perspective view showing the state in which the battery module is assembled in the present invention. FIG. 7 is a structural diagram showing the state in which the gas outlet in FIG. 2 moves in and out. Specific details for implementing the invention

[0036] The following description regarding the present invention is merely an example for structural or functional explanation, and therefore the scope of the present invention should not be interpreted as being limited by the examples specified in the text. That is, since the examples can be modified in various ways and can take various forms, the scope of the present invention should be understood to include equivalents capable of realizing the technical concept.

[0037] Furthermore, the purposes or effects presented in this invention do not imply that specific embodiments must include all of them or only such effects; therefore, the scope of the rights of this invention should not be understood as being limited by them.

[0038] A preferred technical configuration and operation for implementing the present invention will be described in detail below with reference to the attached drawings.

[0039] FIG. 1 is a side view showing the state in which the battery thermal runaway diffusion prevention device of the present invention is mounted on an electric vehicle, FIG. 2a is a plan view showing the state in which the battery thermal runaway diffusion prevention device of the present invention is mounted on an electric vehicle, FIG. 2b is a plan view showing the state in which gas is discharged from the battery module where thermal runaway occurred in FIG. 2a, and FIG. 3 is a side cross-sectional view showing the state in which firefighting water is injected into the battery module where thermal runaway occurred and gas is discharged in the present invention.

[0040] As illustrated herein, the thermal runaway diffusion prevention device for an electric vehicle battery of the present invention is characterized by being composed of a battery pack (100), a battery pack extinguishing device, a connecting pipe (200), a gas induction discharge pipe (230), a extinguishing capsule mixing device (250), a gas discharge port (260), and a control system (610).

[0041] That is, the battery pack (100) installed in the electric vehicle has several battery modules (120) each covered by an upper cover (150) and a lower cover (130) and arranged left and right, and each upper cover (150) has an exhaust hole on one side.

[0042] And as shown in FIG. 3, the lower cover (130) is provided with a fire extinguishing water hole (131) for the inflow of fire extinguishing water on the outside, and is installed on the lower cover (130) so that a fire extinguishing water passage is provided on all sides by a heat-conducting pad (122) that doubles as a shock absorber and is installed in a predetermined size, and as shown in FIG. 2a, a fire detection sensor (600) is installed on one side of the inner surface of the upper cover (150).

[0043] The above connecting pipe (200) is installed by connecting it to the outside of the exhaust hole of the upper cover (150), and as shown in FIG. 3, it is equipped with a sealing blocking material (220) and a backflow prevention valve (210) to prevent foreign substances from entering from the outside under normal circumstances, and when thermal runaway occurs inside the battery module (120), the sealing blocking material (220) is removed by the fire and gas pressure, and the gas and fire are discharged through the backflow prevention valve (210), thereby acting as an explosion-prevention safety valve or a one-way vent cap.

[0044] As shown in FIG. 2B, the above battery pack fire extinguishing device is provided by branching a fire extinguishing water supply pipe (500) from a cooling water circulation pipe (430) to which the cooling water of a cooling water tank (400) provided in a vehicle is supplied, and fire extinguishing water automatic opening / closing nozzles (510) arranged at predetermined intervals in the fire extinguishing water supply pipe (500) are connected to fire extinguishing water holes (131) of each lower cover (130) so that the cooling water of the cooling water tank (400) can be used as fire extinguishing water.

[0045] Here, the coolant in the coolant tank (400) used as the fire extinguishing water is a coolant (antifreeze) used to cool electric vehicle motors, inverters, batteries, etc., and if all of these coolants are included, the coolant can be used as fire extinguishing water amounting to about 18 to 20 liters.

[0046] Here, the fire extinguishing water supply pipe (500) may be connected to an external pipe (540) equipped with a third valve (550) and a one-touch socket (520) as shown in FIG. 2b, and fire extinguishing water may be supplied from the outside to the thermal runaway area through an external inlet hose (560) connected to the one-touch socket (520) by a one-touch plug (570).

[0047] Then, fire extinguishing water can be continuously supplied through an external inlet hose (560) connected to an external fire extinguishing water supply device, making it very effective for fire suppression.

[0048] The above gas induction exhaust pipe (230) is preferably installed by securing a mounting space between the left and right battery modules (120), and is connected to the left and right connecting pipes (200) facing each other to discharge fire or flames caused by thermal runaway inside the battery modules (120) to the outside.

[0049] The above-mentioned fire extinguishing capsule mixing device (250) is installed at the rear end of the gas induction discharge pipe (230), and capsules containing fire extinguishing liquid are filled inside so that when gas caused by thermal runaway passes through, the fire extinguishing liquid inside the capsules is discharged in a mixed state.

[0050] The above gas outlet (260) is installed at the rear of the fire extinguishing capsule mixing device (250) and is installed so that it is exposed from inside the vehicle body to the outside by means of movement and return and then returns to its original position.

[0051] As shown in FIG. 7, the gas outlet (260) is preferably installed so as to be slidable on the rear outer surface of the gas induction discharge pipe (230) as a means of movement and return, and a perforated plate (270) and a spring (280) are provided inside the gas outlet (260).

[0052] The above control system (610) receives a signal from a fire detection sensor (600) as shown in FIGS. 2a and 2b and controls the operation of the first valve (420) of the cooling water circulation pipe (430), the second valve (530) of the fire extinguishing water supply pipe (500), and the circulation pump (410).

[0053] In the drawing, the unexplained reference numeral (110) is a pack lower frame, and (122) is a heat-conducting pad that doubles as a shock absorber and is installed on the upper surface of the lower cover (130) to support the battery module (120), with a size that has fire extinguishing water passages on all sides, and normally absorbs shock transmitted to the battery module (120) and, when thermal runaway occurs, transmits the heat of the battery module (120) to the injected fire extinguishing water.

[0054] And (140) is a cooling water circulation path formed in a zigzag pattern on the bottom surface of the lower cover (130), (440) and (450) are a cooling water inlet nozzle and a cooling water circulation nozzle provided on the pack lower frame (110) to be connected to the cooling water circulation path (140), and (460) is a cooling water return pipe, and it is preferable to use a 3-way valve for the first valve (420) and the second valve (530).

[0055] In the present invention formed in this manner, when no fire occurs, the automatic fire water opening / closing nozzle (510) of the fire water supply pipe (500) blocks the fire water hole (131) of each lower cover (130), and the sealing blocking material (220) installed in the connecting pipe (200) blocks the exhaust hole of the upper cover (150), so there is no risk of foreign substances such as rainwater, wind, or dust penetrating into the battery module (120) from the outside through the fire water hole or exhaust hole.

[0056] And normally, the cooling water of the cooling water tank (400) circulates in a zigzag pattern through the cooling water inlet nozzle (440) and cooling water circulation nozzle (450) provided in the pack lower frame (110) and then returns to the cooling water tank (400) through the cooling water return pipe (460).

[0057] Then, when a thermal runaway phenomenon occurs in any one of the multiple battery modules (120) arranged as in FIGS. 2 and 3, a fire detection sensor (600) placed there sends a fire occurrence signal to the control system (610), so that the first valve (420) on the side of the cooling water circulation pipe (430) is closed and the second valve (530) on the side of the fire extinguishing water supply pipe (500) is opened, so that the cooling water of the cooling water tank (400) is supplied as fire extinguishing water into the battery module (120) through the fire extinguishing water hole connected to the fire extinguishing water automatic opening / closing nozzle (510) of the fire extinguishing water supply pipe (500), thereby suppressing the thermal runaway phenomenon.

[0058] Here, if a valve is installed in each automatic fire extinguishing water opening / closing nozzle (510) connected to the fire extinguishing water hole of each battery module and the control system (610) is configured to open only the valve on the side of the battery module (120) where thermal runaway has occurred, fire extinguishing water can be supplied only to the side of the battery module (120) where thermal runaway has occurred.

[0059] As described above, the supplied fire extinguishing water is filled into the space between the battery module (120), the upper cover (150), and the lower cover (130). Since a fire extinguishing water shut-off gasket (330) is installed in the space between the battery module (120) and the upper cover (150) on both outer sides covered by the separation wall pad (310), the fire extinguishing water injected through the automatic fire extinguishing water opening / closing nozzle (510) is filled only up to a predetermined height.

[0060] Here, the battery module (120) is installed in a state supported by a support so as to have a certain gap with the lower cover (130), so that fire extinguishing water is filled through the gap into each battery module (120) up to the height where the fire extinguishing water shut-off gasket (330) is located.

[0061] Here, each of the above-mentioned battery modules (120) is supported by a heat-conducting pad (122) that doubles as a shock absorber and is installed in a predetermined size as shown in FIG. 3, wherein the battery cells (121) that form a bundle are arranged in multiple bundles as shown in FIG. 4 and FIG. 5, with a predetermined spacing between each bundle, and fire extinguishing water passages are provided on all sides of the heat-conducting pad (122) on the upper surface of the lower cover (130) so that fire extinguishing water is supplied to the multiple battery modules (120).

[0062] The above-mentioned shock-absorbing and heat-conducting pad (122) normally absorbs shocks transmitted to the battery module (120) and, when thermal runaway occurs, serves to transfer heat from the battery module (120) to the injected fire extinguishing water.

[0063] The above-mentioned gap is a space into which the side portion of the separation wall pad (310) is fitted, and using this, the side and top surfaces of each bundled battery module (120) are covered by a separation wall pad (310) having passages on the inner and outer surfaces in an uneven shape like corrugated cardboard.

[0064] In addition, a fire extinguishing water blocking material (320) that dissolves at a certain temperature is provided on a part of the side of the separation wall pad (310), so that when a thermal runaway occurs, the fire extinguishing water blocking material (320) dissolves and opens a passage through which fire extinguishing water is supplied to suppress the thermal runaway.

[0065] Here, the lower end of the fire extinguishing water blocking material (320) must be installed lower than the fire extinguishing water blocking gasket (330) as shown in FIG. 3, and normally it blocks the inflow of fire extinguishing water and foreign substances, and in the event of thermal runaway, it melts and flows to open the passage, acting as a safety valve.

[0066] That is, when a thermal runaway occurs in any of the battery modules (120), the fire extinguishing water blocking material (320) on the side of the separating wall pad (310) covering both sides of the battery module (120) at that location melts due to the heat from the thermal runaway, creating an open passage. Since the bottom of the passage is lower than the level of the fire extinguishing water filled up to the height of the fire extinguishing water blocking gasket (330), the fire extinguishing water is easily supplied into the battery module (120) where the thermal runaway occurred through the open passage to suppress the fire.

[0067] Here, the separator pad (310) is characterized by having a physical insulating layer to prevent heat diffusion between battery cells or being formed of an iron plate material coated with a heat-resistant material.

[0068] In addition, if the fire extinguishing water blocking material (320) of the separation wall pad (310) is formed from a low-melting point metal alloy pellet (Fusible Alloy Pellet) that melts at a set melting temperature, the fire extinguishing water blocking material (320) can melt easily when thermal runaway occurs, allowing the fire extinguishing water to be injected effectively, thereby increasing the fire suppression effect.

[0069] The fire extinguishing water blocking material (320) formed from the above low-melting point metal alloy pellets is capable of discharging internal pressure through a passage formed as the metal melts and flows when it reaches a set temperature (e.g., 124°C), and is inserted into the inner groove of a metal vent cap, and can be inserted between the separation wall pads (310) by high-temperature extrusion or casting.

[0070] In addition, the above-mentioned fire extinguishing water blocking material (320) may be formed into a wax plug (PCM Wax-Plug) that is easily liquefied at a certain temperature to open the flow path.

[0071] The fire extinguishing water blocking material (320) formed by the above wax plug is heat-sensitive and has a structure in which the hole of the separation wall pad (310) made of a metal casing is blocked with wax. In the event of a thermal runaway, the wax melts and flows down quickly, opening the hole and allowing the internal pressure to be released quickly, making it suitable for allowing gas to be discharged more quickly.

[0072] In addition, the above-mentioned fire extinguishing water blocking material (320) can be formed as heat-triggered microcapsules that act as heat reaction triggers, so that when a thermal runaway occurs, the fire extinguishing water blocking material (320) can be easily dissolved and fire extinguishing water can be injected.

[0073] The above-mentioned heat-actuated microcapsule contains a melting material inside, and it is easy to install a melting point between 110°C and 140°C.

[0074] In this invention, when fire and gas are generated inside the battery module (120) due to thermal runaway, the sealing blocker (220) blocking the exhaust hole is removed by the pressure, so the fire and gas are guided to the gas induction discharge pipe (230) through the backflow prevention valve (210) and discharged.

[0075] At this time, a fire extinguishing capsule mixing device (250) containing capsules filled with fire extinguishing liquid is installed at the rear end of the gas induction discharge pipe (230). Therefore, as the discharged fire and gas pass through the fire extinguishing capsule mixing device (250) and are mixed with the fire extinguishing liquid, there is little risk of explosion when discharged to the outside.

[0076] And when the fire and gas discharged through the above gas induction discharge pipe (230) reach the gas discharge port (260) and reach the internal perforated plate (270), the gas discharge port (260) is pushed backward by the pressure of the fire and gas while compressing the spring (280), so that the end of the gas discharge port (260) is moved to be exposed to the outside of the vehicle body. Therefore, the fire and gas discharged through the gas discharge port (260) can be discharged to the outside without affecting the vehicle body, so there is no risk of explosion.

[0077] And when such gas pressure is released, the gas outlet (260) is quickly returned to its original position by the tension of the spring (280).

[0078] The present invention provides gas induction discharge pipes (230) equipped with a gas outlet (260) and a fire extinguishing capsule mixing device (250) at the front and rear of an electric vehicle, and installs a valve in each gas induction discharge pipe (230) so that fire and gas can be discharged to either the front or the rear or both.

[0079] Then, under the control of the vehicle control unit receiving signals from obstacle detection sensors installed on the front and rear bumpers of the vehicle body, the check valve on the side with more damage between the front and rear is closed, and the check valve on the side with no or minor damage is opened to discharge fire and gas, thereby significantly reducing damage.

[0080] Although the invention made by the inventors has been specifically described according to the above embodiments, it is obvious to those skilled in the art that the invention is not limited to the above embodiments and can be modified in various ways without departing from the gist thereof. Explanation of the symbols

[0082] 100 : Battery pack 110 : Pack bottom frame 120 : Battery module 121 : Battery cell 122 : Thermal conductive pad with shock absorption function 130 : Lower cover 131 : Fire extinguishing water hole 140 : Coolant circulation path 150 : Upper cover 200 : Connecting pipe 210 : Check valve 220 : Sealing barrier 230 : Gas induction exhaust pipe 250 : Fire extinguishing capsule mixing device 260 : Gas exhaust port 270 : Perforated plate 280 : Spring 310: Partition wall pad 320: Fire extinguishing water barrier 330 : Fire extinguishing water shut-off gasket 400 : Cooling water tank 410: Circulation pump 420: First valve 430: Coolant circulation pipe 440: Coolant inlet nozzle 450: Coolant circulation nozzle 460: Coolant return pipe 500: Firefighting water supply pipe 510: Firefighting water automatic shut-off nozzle 520 : One-touch socket 530 : Second valve 540 : External piping 550 : 3rd valve 560: External inlet hose 570: One-touch plug 600 : Fire detection sensor 610 : Control system

Claims

Claim 1 A battery pack (100) mounted on an electric vehicle, wherein multiple battery modules (120) are each covered by upper and lower covers (150) (130) and arranged on the left and right sides, an exhaust hole is provided on one side of the upper cover (150), a fire extinguishing water hole (131) is provided on the outer side of each lower cover (130), and fire extinguishing water passages are provided in all directions by a heat-conducting pad (122) that doubles as a shock absorber and is installed in a predetermined size, and a fire detection sensor (600) is installed for each module; and fire extinguishing water automatic opening / closing nozzles (510) arranged at predetermined intervals in a fire extinguishing water supply pipe (500) branched from the cooling water circulation pipe (430) of the cooling water tank (400) provided in the electric vehicle are connected to the fire extinguishing water holes (131) of each lower cover (130) so that the cooling water of the cooling water tank (400) can be used for fire extinguishing water. A battery pack fire extinguishing device; a connecting pipe (200) installed on the outside of each exhaust hole of the upper cover (150); a gas induction discharge pipe (230) connected to the connecting pipe (200) to induce and discharge heat and gas generated by thermal runaway to the outside; a gas discharge port (260) installed at the rear of the gas induction discharge pipe (230) to discharge gas discharged through the gas induction discharge pipe (230) to the outside of the vehicle body; and a control system (610) that receives a signal from a fire detection sensor (600) and controls the operation of a first valve (420) of a cooling water circulation pipe (430), a second valve (530) of a fire extinguishing water supply pipe (500), and a circulation pump (410). The device is characterized by being configured to quickly suppress thermal runaway when it occurs and to prevent it from spreading to other places. Claim 2 In claim 1, the battery module (120) is configured with multiple battery cells (121) forming a bundle, and is installed on a lower cover (130) such that a fire extinguishing water passage is secured on the bottom surface while a predetermined spacing is provided between each bundle, and the two sides and top surface of each bundled battery cell (121) are covered by a separating wall pad (310) having an uneven passage provided using the spacing, and a fire extinguishing water blocking material (320) that dissolves at a certain temperature is provided on a part of the side of the separating wall pad (310), so that when a thermal runaway occurs, the fire extinguishing water blocking material (320) dissolves and opens, thereby supplying fire extinguishing water through the opening to suppress the thermal runaway. This characterizes the thermal runaway prevention device for an electric vehicle battery. Claim 3 A thermal runaway diffusion prevention device for an electric vehicle battery according to claim 1 or 2, characterized in that the connecting pipe (200) normally blocks the exhaust hole of the upper cover (150) to prevent foreign substances such as rainwater, wind, and dust from entering from the outside, and is equipped with a sealing blocking material (220) and a backflow prevention valve (210) to open by the internal pressure of the battery in the event of a battery fire. Claim 4 A thermal runaway prevention device for an electric vehicle battery, characterized in that, in claim 1 or 2, the fire extinguishing water supply pipe (500) is connected to an external pipe (540) equipped with a third valve (550) and a one-touch socket (520), and fire extinguishing water can be supplied from the outside to the thermal runaway occurrence site through an external inlet hose (560) connected to the one-touch socket (520) by a one-touch plug (570). Claim 5 A thermal runaway diffusion prevention device for an electric vehicle battery according to claim 1 or 2, wherein the gas outlet (260) is installed to slide at the rear of the gas induction discharge pipe (230) as a means of movement and return, and the gas outlet (260) is provided with a perforated plate (270) and a spring (280) inside the gas outlet (260) so that when the pressure of fire and gas reaches the perforated plate (270) due to the occurrence of a fire, the gas outlet (260) moves backward while compressing the spring (280), and when the gas pressure is released, it returns to its original position by the tension of the spring (280). Claim 6 In claim 2, the separator pad (310) is characterized by having a physical insulating layer to prevent heat diffusion between battery cells or being formed of an iron plate material coated with a heat-resistant material, thereby preventing thermal runaway diffusion of an electric vehicle battery. Claim 7 In claim 2, a fire extinguishing water blocking gasket (330) is installed in the space between the outer battery modules (120) and the upper cover (150) on both sides wrapped by the separation wall pad (310) so that the fire extinguishing water injected through the automatic fire extinguishing water opening / closing nozzle (510) is filled only up to a predetermined height, and a fire extinguishing water blocking material (320) is installed so that its lower end is positioned lower than the fire extinguishing water blocking gasket (330) by a predetermined height, characterized in that it is a thermal runaway diffusion prevention device for an electric vehicle battery. Claim 8 A thermal runaway diffusion prevention device for an electric vehicle battery according to claim 1 or 2, wherein the gas induction discharge pipe (230) is characterized by having a fire extinguishing capsule mixing device (250) installed at a rear end adjacent to the gas discharge port (260), the device being filled with capsules containing fire extinguishing liquid and mixing the fire extinguishing liquid when heat and gas pass through. Claim 9 In claim 2, the fire extinguishing water blocking material (320) of the separation wall pad (310) is formed from any one of a low-melting point metal alloy pellet (Fusible Alloy Pellet) that melts at a set melting temperature, a wax plug (PCM Wax-Plug) that liquefies at a certain temperature to open a flow path, and a heat-triggered microcapsule (Heat-Triggered Capsule) that acts as a superheat reaction trigger, thereby preventing thermal runaway diffusion of an electric vehicle battery. Claim 10 A thermal runaway diffusion prevention device for an electric vehicle battery, characterized in that, in claim 1 or 2, a gas induction discharge pipe (230) equipped with a gas discharge port (260) and a fire extinguishing capsule mixing device (250) is provided at the front and rear of the electric vehicle, and an electric valve controlled by a control system (610) is installed in each gas induction discharge pipe (230) so that fire and gas discharge can be selected to either the front or rear of the vehicle body or both.

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