JP2014165026A - Fire extinguisher - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress expansion of fire incident to thermal runaway of a lithium ion battery, by mounting a fire extinguisher on the lithium ion battery.SOLUTION: A fire extinguisher 12 is mounted detachably on a lithium ion battery, including a safety valve opening when the internal pressure of a battery outer container rises, while covering the outside of the safety valve. The fire extinguisher 12 includes an adsorption filter 34 using anti-inflammatory metal meshes 30a, 30b and a glass wool arranged relatively to the safety valve 14. Flame of an electrolyte ejected by action of the safety valve 14 is extinguished by the anti-inflammatory metal meshes 30a, 30b and the electrolyte passed through the anti-inflammatory metal meshes 30a, 30b is adsorbed by the adsorption filter 34 using heat-resistant fibers and held so that it is scarcely ejected from an exhaust port 28.

Description

  The present invention relates to a fire extinguishing apparatus that suppresses the spread of fire due to thermal runaway of a lithium ion battery.

In recent years, hybrid vehicles equipped with engines and motors are rapidly increasing in addition to vehicles powered by engines powered by gasoline or light oil. Furthermore, in addition to such hybrid vehicles, electric vehicles that use only electric motors as the power source and have zero CO ₂ emissions during travel are gradually becoming popular.

  A high-voltage and large-capacity power storage device in which a plurality of single cells are arranged and connected in series and in parallel is mounted on the body of a hybrid vehicle or an electric vehicle. The power storage device is composed of an assembled battery in which a plurality of unit cells called cells are connected, and is housed in a sealed container. In addition, the unit cell mounted in the power storage device has shifted from a conventional nickel-hydrogen battery to a lithium ion battery that can be charged even in a general home, and it is expected that the unit cell will have higher performance in the future.

  Also, in the field of aircraft, an aircraft equipped with a power storage device using a lithium ion battery that is small in size and has a large capacity and contributes to weight reduction has been put into practical use and has started operation.

  Furthermore, in recent years, power storage devices using stationary lithium ion batteries for general homes, offices, public facilities, and the like are also rapidly spreading.

JP 2000-188135 A JP 2012-252839 A JP 2011-254906 A JP 2012-009317 A JP 2011-165628 A

  However, in such a lithium ion battery, when the thermal runaway occurs due to various causes such as an internal short circuit or overcharge, the battery temperature rises remarkably and the internal pressure of the battery rises. As a result, the lithium ion battery There is a risk that an electric fire with the lithium ion battery as the source of fire may occur due to the fire of the electrolyte solution ignited when the safety valve provided in is activated (exploded).

  Lithium ion batteries use flammable liquids such as dimethyl carbonate and diethyl carbonate as the electrolyte, and as long as there are flammable liquids, they ignite when conditions are met. The ignition mechanism of lithium-ion batteries is thermal runaway, and the internal temperature of the cell increases due to internal short circuit, abnormal heating inside the cell, external short circuit, external abnormal overheating, excessive current, excessive voltage, etc. When this exotherm exceeds a certain limit value, the behavior cannot be controlled and the temperature rising reaction is continuously caused and the temperature rising phenomenon occurs. This is a thermal runaway.

  The behavior of a lithium-ion battery during thermal runaway shows a rapid temperature rise reaction in a short time, the electrolyte is heated suddenly, expands, gasifies and ejects, and the safety valve provided in the cell is activated (ruptured). The electrolyte is ejected, and the flame is ejected from the cell because the electrolyte is a flammable liquid.

  It has been reported as a result of various fire experiments that the degree of the flame ejected from the cell varies depending on the charge amount of the lithium ion battery. The amount of oxygen released at the time of exothermic decomposition of a lithium ion battery differs depending on the state of charge, and it is said that the amount of released oxygen is greatest when fully charged (SOC 100%). For this reason, there is a difference in the amount of oxygen released between a battery with a large amount of charge and a battery with a small amount of charge. The larger the amount of charge, the stronger the flame is emitted from the cell, and the full charge causes an explosive flame. ing.

By the way, in the manufacturing process of a lithium ion battery, conductive foreign matters such as metal powder may be mistakenly mixed inside the battery. When such a lithium ion battery is used, dent light caused by the conductive foreign matter is used. Occurs, causing an internal short circuit and causing thermal runaway.
Therefore, an aging process is provided in the final process of manufacturing the lithium ion battery, and it is inspected whether or not conductive foreign matter is mixed in the battery to remove defective products.

  In the aging process, after the lithium ion battery is assembled, initial charge (full charge to SOC 100%) is performed, and then the battery is left for a predetermined time at a predetermined environmental temperature to obtain a voltage drop amount. When the voltage drop amount is larger than a reference value Determines that conductive foreign matter is mixed in the battery and removes it as a defective product.

  In such an aging process, there is a possibility that thermal runaway may occur due to an abnormality associated with the initial charging of the lithium ion battery, and the safety valve is activated (exploded) due to thermal runaway, and the atomized electrolyte is ejected and further ejected. Ignite the charge liquid and spout a flame. In the aging process, a large number of initially charged lithium ion batteries are left side by side, so if one of them causes a thermal runaway, the sprayed electrolyte flame scatters around and heats other lithium ion batteries. In addition, the electrolytic solution adhering between the electrodes may cause an external short circuit, and as a result, the thermal runaway may occur in a chain and spread to a large fire. In the past, a large fire accident has been reported.

  Various safety measures are taken against the problem of ignition due to such thermal runaway, and safety is improved every day. In this regard, “It is true that the safety of the battery can be improved. However, the probability of a fire / explosion is reduced, and it does not mean that there will be no fire / explosion”. The views of those who have academic experience are also shown.

  With respect to a fire caused by thermal runaway of a lithium ion battery in the manufacturing process, in Patent Document 1, a fire is detected and a fire extinguishing gas is released for each shelf in which a large number of batteries to be aged are arranged. When gas fires are difficult to extinguish, we have proposed an aging device that can extinguish a fire by releasing foam extinguishing liquid and treat battery fires on a shelf-by-shelf basis. However, there is a possibility that a large number of batteries arranged on the shelf that caused the fire may burn out from the fire, and the danger due to the fire when the lithium ion battery causes a thermal runaway has not been eliminated.

  In addition, the fire due to the thermal runaway of the lithium ion battery, for example, in the adjustment process and inspection process after the aging process is completed, and also in the stage of waiting for the factory to leave, for example, the lithium ion battery is in a charged state of about 50%, There is no possibility of thermal runaway due to any abnormality, and countermeasures are strongly desired.

  It is an object of the present invention to provide a fire extinguishing apparatus that is capable of preventing the expansion of a large fire by suppressing the flame of the electrolytic solution that is ejected due to thermal runaway and the scattering of the electrolytic solution by being attached to a lithium ion battery. Objective.

(Fire extinguishing equipment)
The present invention relates to a fire extinguishing device attached to a unit cell provided with a safety valve that is opened when the internal pressure of the battery outer container rises.
A housing that covers the outside of the safety valve and is detachably attached to the battery outer container, and has a discharge port at an outer position away from the safety valve;
An extinguishing metal net disposed on the safety valve side in the housing and extinguishing the flame of the electrolyte sprayed by the operation of the safety valve of the cell,
An adsorption filter using heat-resistant fibers that are arranged in the housing following the flame-extinguishing metal mesh and adsorb and hold the electrolyte that has passed through the flame-extinguishing metal mesh,
It is provided with.

(Net structure of flame-retardant metal mesh)
The flame-extinguishing metal mesh has a mesh structure in which the mesh size decreases from the receiving side of the electrolyte flame in the depth direction.

(Suction filter)
The heat resistant fiber of the adsorption filter is glass wool.

(Powder extinguishing agent)
Store powder fire extinguisher in the housing. The powder fire extinguisher is filled in a sealed bag that melts and breaks by receiving heat from the flame of the electrolyte sprayed by the operation of the safety valve of the unit cell. Place inside or rear.

(Fire detection means)
Fire extinguishing equipment,
A fire sensor unit that is provided in the housing and detects heat generated by the flame of the electrolyte sprayed by the operation of the safety valve of the unit cell and outputs a detection signal;
A fire detection circuit unit that detects a fire based on a detection signal output from the sensor means and outputs a fire detection signal; and
And provide.

  The fire sensor unit is a heat sensing cable that detects a fire by bringing a pair of signal wires into short-circuited condition by melting the insulation coating when receiving heat from a flame. The cable is laid so as to pass through and connected to a connector provided on the casing, and the heat sensing cable is connected to a fire detection circuit portion provided outside the casing through the connector.

(Electrode lead member)
The fire extinguisher is further provided with an electrode lead member having one end in contact with the electrode terminal of the unit cell and the other end taken out of the housing, and an insulating coating is provided in the middle of the electrode lead member so as not to contact the housing. .

(Basic effect)
The fire extinguisher of the present invention covers the outside of a safety valve provided in a lithium ion battery, for example, as a unit cell and attaches it to the battery outer container, so that the lithium ion battery causes a thermal runaway and the safety valve is activated and the electrolyte flame The flame of the electrolyte passes through the flame-extinguishing metal mesh placed in the fire extinguishing device, and the flame disappears in the middle of the flame to form an atomized electrolyte. Other lithium-ion batteries that are adsorbed and removed through the used adsorption filter, hardly emit any flame to the outside from the discharge port of the housing, can greatly reduce the ejection of electrolyte, and are arranged around the aging process etc. This ensures that chain thermal runaway due to heating of the battery is prevented, and that the electrolyte does not adhere between the electrode terminals of other lithium-ion batteries, thus ensuring chain thermal runaway due to external short circuit due to the electrolyte. Preventing, the damage from the fire bear in a lithium ion battery that caused the thermal runaway allows prevented from being expanded to a large fire.

(Effects of network structure of flame-retardant metal mesh)
The extinguishing metal mesh has a mesh structure that reduces the mesh size from the receiving side of the electrolyte flame in the depth direction, so that the flame of the electrolyte that blows in is surely extinguished and the jet flows with resistance due to the smaller mesh. The fine particles of the electrolytic solution can be adhered and held on the network that is becoming smaller and smaller.

(Effect of glass wool on adsorption filter)
In addition, by using glass wool as the heat-resistant fiber for the adsorption filter, it has high heat resistance against the jet of high-temperature electrolyte and adsorbs and holds fine particles of the electrolyte, greatly reducing the electrolyte discharged from the discharge port. Reduce.

(Effect of powder fire extinguishing agent)
Moreover, by storing the powder fire extinguisher in the casing, it is possible to suppress the fire of the electrolyte solution ejected from the safety valve of the lithium ion battery by the powder fire extinguisher. The powder extinguishing agent is placed in the front, inside or rear of the flame extinguishing metal mesh by filling it in a sealed bag that melts and breaks by receiving the heat from the flame of the electrolyte sprayed by the operation of the safety valve of the cell. By filling the bag, the powder digester does not absorb moisture and solidify or deteriorate, and when the packaging bag melts due to the flame of the electrolyte, the powder extinguisher diffuses and entrains the flame Can reliably suppress fire extinguishing.

(Effects of fire detection means)
In addition, since the fire sensor unit and fire detection circuit unit are installed in the fire extinguisher, the fire due to thermal runaway of the lithium-ion battery is monitored by an external device, and the fire that occurs in the aging process that is unattended monitoring is detected and reliably detected. Can be alarmed.

(Effect of heat sensing cable)
The fire sensor section is a heat sensing cable that detects a fire by bringing a pair of signal wires into short-circuited condition by melting the insulation coating when receiving heat from a flame. Necessary when using a temperature sensor, etc. This eliminates the need for setting a threshold temperature for detecting a simple fire and comparing and judging the threshold and the detected temperature, and can easily and reliably detect a fire of a lithium ion battery.

Explanatory drawing showing the appearance of a fire extinguisher attached to a rectangular lithium ion battery with a safety valve on top 1 is a cross-sectional view showing a plane, a vertical and a horizontal cross section of the fire extinguishing apparatus of FIG. 1 is a cross-sectional view showing an assembled and disassembled state of the fire extinguisher of FIG. 1 for a lithium ion battery. Explanatory drawing which showed operation | movement of the fire extinguisher of FIG. Explanatory drawing showing the aging process of a lithium-ion battery equipped with a fire extinguisher Circuit diagram showing the fire detection circuit of FIG. Cross-sectional view showing a fire extinguisher containing a powder extinguisher together with a lithium ion battery Explanatory drawing which showed operation | movement of the fire extinguishing apparatus of FIG. Explanatory drawing showing the appearance of a fire extinguisher attached to a rectangular lithium ion battery with a safety valve on the side Sectional drawing which showed the cross section of the fire extinguishing apparatus of FIG. 9 with the lithium ion battery Explanatory drawing which showed the assembly / disassembly state of the fire extinguisher of FIG. 9 with respect to a lithium ion battery Explanatory drawing which showed operation | movement of the fire extinguisher of FIG. Sectional drawing which showed embodiment of the fire extinguisher attached to the cylindrical lithium ion battery Explanatory drawing which showed operation | movement of the fire extinguisher of FIG. Sectional view showing a fire extinguisher attached to a cylindrical lithium-ion battery containing a powder fire extinguisher Sectional drawing which showed embodiment of the fire-extinguishing apparatus provided with the electrode extraction structure with respect to a cylindrical lithium ion battery

FIG. 1 shows the appearance of a fire extinguisher mounted on a rectangular lithium ion battery having a safety valve on the upper end surface, a plane (FIG. 1 (A)), a front (FIG. 1 (B)), and a side (FIG. 1 (C)). FIG. 2 is a plan sectional view (FIG. 2A), a longitudinal section (FIG. 2B), and a transverse section (FIG. 2C) of the fire extinguishing apparatus of FIG. 1 mounted on a lithium ion battery. FIG. 3 is a cross-sectional view showing each section of FIG. 1, and FIG. 3 is a cross-sectional view showing an assembled and disassembled state of the fire extinguisher of FIG. 1 for a lithium ion battery.

(Outline of lithium-ion battery)
As shown in FIGS. 1, 2 and 3, a lithium ion battery 10 is a non-aqueous electrolyte secondary battery known as a single battery (battery cell), for example, a rectangular type formed of aluminum or an aluminum alloy. The electrode body is housed in the outer container together with the electrolytic solution. As the electrolytic solution, a flammable organic solvent such as dimethyl carbonate or diethyl carbonate is used, and a mixed solution in which a plurality of kinds of organic solvents are mixed at various ratios is used, and has high conductivity.

  The electrode body of the lithium ion battery 10 is formed into a rectangular shape by, for example, winding a positive electrode plate and a negative electrode plate in a spiral shape with a separator interposed therebetween, and the separator is impregnated with an electrolytic solution. A pair of electrode terminals 16 a and 16 b serving as a positive electrode and a negative electrode are taken out from the upper end of the outer casing of the lithium ion battery 10. A safety valve 14 is provided on the upper partition wall of the lithium ion battery 10. The safety valve 14 has an opening provided in the outer container closed with a thin aluminum plate, or a portion of the safety valve 14 is processed to be thin, and an X-shaped groove is formed as necessary, and internal pressure is reduced due to thermal runaway or the like. When increased, it operates (ruptures) at a predetermined pressure to prevent the outer container from bursting.

  Here, the outer size of the lithium ion battery 10 is, for example, a large type for an aircraft, for example, (height = 170 mm to 180 mm) × (width = 130 mm to 140 mm) × (depth = 50 mm to 60 mm). Become.

  The lithium ion battery 10 is used by being housed in a power storage device known as a battery module or a battery pack. In the case of an aircraft power storage device, for example, eight batteries are stored in a storage container, and the average cell voltage of a lithium ion battery is, for example, 3.5 volts. Is 28 volts. Note that the number of lithium ion batteries used in the power storage device corresponds to the required voltage.

(Configuration of fire extinguishing device)
As shown in FIGS. 1, 2, 3, and 4, the fire extinguishing device 12 is formed of a metal plate, covers the outside of the safety valve 14 provided on the upper end surface of the lithium ion battery 10, and serves as a battery outer container. A detachable casing 18 is provided, and a skirt-shaped holding portion 20 is integrally formed on the lower side of the casing 18, and is detachably provided on the lithium ion battery 10 by the holding portion 20.

  As shown in FIG. 3, the holding part 20 is formed with a pressing part 20a bent inward at the skirt-shaped tip. When the holding part 20 is inserted into the lithium ion battery 10 from above, the pressing part 20a causes the side of the battery outer container to be It is possible to secure a predetermined mounting strength by sandwiching. In addition, rectangular openings 22 are formed on both sides of the upper end surface of the hold unit 20 in order to expose the electrode terminals 16a and 16b of the lithium ion battery 10 to the outside.

  Following the hold unit 20, in order to expose the electrode terminals 16a and 16b of the lithium ion battery 10 to the outside, a small rectangular cavity 24a is formed, and a large rectangular cavity having a sealed structure thereon. A portion 24b is formed, and a plurality of discharge ports 28 are formed on the left and right side surfaces and the upper end surface of the rectangular cavity portion 24b.

  The flame extinguishing metal mesh 30a is accommodated in the rectangular accommodating portion 24a of the casing 18, and the flame extinguishing metal mesh 30b is accommodated in the rectangular cavity portion 24b positioned thereon. The flame extinguishing metal nets 30a and 30b are arranged at positions opposite to the safety valve 14 of the lithium ion battery 10 and receive a flame of the electrolyte that is ejected by the operation (rupture) of the safety valve 14 when the lithium ion battery 10 causes thermal runaway. , Block the flame and extinguish it. The mesh of the extinguishing metal meshes 30a and 30b has a mesh structure in which the mesh size becomes smaller from the side receiving the electrolyte flame toward the depth direction.

 With this mesh structure, the flame of the electrolyte sprayed from the safety valve 14 is introduced with less resistance to the coarse mesh of the extinguishing metal mesh 30a located in front, and the mesh becomes finer as it goes to the inner extinguishing metal mesh 30b. The action of blocking the flame and extinguishing the flame is strengthened, and the atomized electrolyte is easily attached. As a specific mesh structure, for example, a structure in which a plurality of metal meshes having different mesh sizes are stacked may be used. Further, although the illustrated embodiment is divided into the extinguishing metal nets 30a and 30b, they may be integrated.

  An adsorption filter 34 using heat-resistant fibers is housed in a rectangular cavity 24b following the flame extinguishing metal mesh 30b. The adsorption filter 34 uses, for example, glass wool, which is a cotton-like material made of short glass fibers, adsorbs atomized electrolyte fine particles passing through the flame-extinguishing metal mesh 30b, and electrolyzes from the discharge port 28 to the outside. Suppresses liquid ejection.

  In addition, a heat sensing cable 38 that functions as a fire sensor unit that detects heat due to the flame of the electrolyte sprayed by the operation of the safety valve 14 of the lithium ion battery 10 is provided inside the housing 18. The heat sensing cable 38 is two twisted signal wires that are insulated and coated with a synthetic resin such as vinyl, and a voltage is applied between the two signal wires from a fire detection circuit section to be described later. When the insulation coating melts when it receives heat, the two signal wires come into contact with the short circuit, and a fire is detected when a sensing current flows.

  One end of two signal wires is connected to a connector 36 provided on the upper side surface of the housing 18 and the heat sensing cable 38 is drawn out to a space covering the safety valve 14 through the adsorption filter 34 and the flame extinguishing metal nets 30b and 30a. It arrange | positions in the position which receives the flame of the electrolyte solution which ejected from 14 directly.

(Fire detection circuit)
FIG. 4 is an explanatory diagram showing an aging process of a lithium ion battery equipped with a fire extinguishing device, and FIG. 5 is a circuit diagram showing a fire detection circuit unit of FIG.

  In the aging process of the lithium ion battery, initial charging (full charge to SOC 100%) is performed after the lithium ion battery 10 is assembled, and then, as shown in FIG. For example, it is arranged in a predetermined aging container 44, the plug 37 of the signal line 45 is connected to the connector 36 of the fire extinguishing device 12, and the signal line 45 is connected to the fire detection circuit unit 46 provided in the aging container 44. Enables monitoring of fire.

 A signal line 48 is drawn out from the fire detection circuit unit 46, and when a fire is detected by one of the fire extinguishing devices 12 provided in the lithium ion battery 10, a fire detection signal is sent to the monitoring panel of a production facility (not shown) by the signal line 48. To fire alarms. The fire detection circuit unit 46 may be installed outside the aging container 44.

  The lithium ion battery 10 equipped with the fire extinguishing device 12 housed in the aging container 44 is left for a predetermined time at a predetermined environmental temperature to obtain a voltage drop amount. If the voltage drop amount is larger than a reference value, it is removed as a defective product. Aging is performed.

  As shown in FIG. 5, the fire detection circuit unit 46 includes a transistor 50, a relay 52, and resistors 54, 55, 56, and 58, and the transistor 50 supplies the divided voltage of the resistors 54 and 55 via the resistor 56. A heat sensing cable 38 applied to the base and provided in a plurality of fire extinguishing devices is connected in parallel via a signal line 45 connected to a connector 36 and a plug 37, and a resistor 54 is connected to the plurality of heat sensing cables 38 connected in parallel. , 55, the power supply voltage + Vc is constantly applied. Here, in the normal monitoring state, the transistor 50 is off, and only one power supply voltage is applied to one of the signal lines of the heat sensing cable 38, and no current is flowing. There is very little current.

  The transistor 50 is a PNP transistor, and a relay 52 is connected as a load on the collector side. In the normal monitoring state, the heat sensing cable 38 is open with an insulation covering of two signal lines such as vinyl. No current flows from the power source, and the transistor 50 is off because the voltage between the emitter and the base is 0 volts.

  The relay 52 connects the normally open relay contact 60 between the collector and power supply line of the transistor 50 to form a latch circuit. The relay 52 has a normally open relay contact 62 for outputting a fire detection signal to the outside.

  As shown in FIG. 5, when any of the lithium ion batteries 10 undergoes thermal runaway during aging, and the flame of the electrolyte is ejected from the activated safety valve 14, the fire extinguishing device 10 provided opposite to the safety valve 14. When the heat sensing cable 38 is subjected to the flame of the electrolytic solution and the vinyl which is the insulation coating melts and the two signal lines are brought into contact with each other, a current flows through the heat sensing cable 38 via the resistors 54 and 55.

  For this reason, a bias voltage is applied between the emitter and base of the transistor 50 by the voltage generated in the resistor 54, whereby the transistor 50 is turned on and the relay 52 is activated. When the relay 52 is activated, the normally open relay contact 60 is closed and the relay 52 is latched, and the normally open relay contact 62 is closed and a fire detection signal is output from the signal line 48 to the outside. The occurrence is notified.

(Operation of fire extinguishing device)
FIG. 6 is an explanatory diagram showing the operation of the fire extinguishing apparatus when the electrolyte solution is ejected due to thermal runaway of the lithium ion battery. If the lithium ion battery 10 causes a thermal runaway and the safety valve 14 is activated (ruptures), and the electrolyte that has been filled ignites and causes a fire to blow out the flame violently, the flame of the electrolyte that is ejected from the safety valve 14 is Then, the flame enters the flame extinguishing metal mesh 30a, 30b provided in the fire extinguishing apparatus 12, and the flame is interrupted and disappears while passing through the flame extinguishing metal mesh 30a, 30b. Adhere and hold. Subsequently, the fine particles of the electrolyte solution in the atomized state that have passed through the flame-extinguishing metal net 30b enter the adsorption filter 34 using glass wool and are adsorbed and held, thereby greatly suppressing the discharge of the electrolyte solution from the discharge port 28 to the outside.

  For this reason, even if the lithium ion battery 10 runs away during aging, and the flame of the electrolyte solution is ejected by the operation of the safety valve 14, the flame is extinguished in the fire extinguishing device 12, and the flame is prevented from being ejected to the outside. It is possible to reliably prevent chain thermal runaway due to heating of other lithium ion batteries disposed in the surroundings, and to prevent damage caused by fire in the lithium ion battery that caused thermal runaway.

  Further, the electrolytic solution ejected from the lithium ion battery 10 is adsorbed and held in the fire extinguishing apparatus 12, and the amount ejected to the outside is greatly reduced, and the electrolytic solution ejected outside is between the electrode terminals 16 a and 16 b of the other lithium ion batteries 10. It is possible to reliably prevent the occurrence of an external short circuit and to prevent chain thermal runaway due to the external short circuit. Further, even if a part of the electrolyte solution is ejected from the fire extinguishing device 12 of the lithium ion battery 10 that has caused thermal runaway, the casing of the fire extinguishing device 12 above the electrode terminals 16 a and 16 b of the other lithium ion batteries 10. 18 is located, and thereby adhesion of the electrolyte can be suppressed.

  In addition, the electrolyte flame sprayed from the safety valve 14 melts vinyl, which is the insulation coating of the heat sensing cable 38, causes the two signal lines to be in contact with each other, current flows through the heat sensing cable 38, and this is detected to detect fire. The circuit unit 46 outputs a fire detection signal to the outside, and a fire alarm is output from the monitoring panel of the production facility, etc., enabling the staff to know the ignition of the lithium ion battery 10 during aging and appropriately deal with it.

(Embodiment of fire extinguishing apparatus provided with powder fire extinguishing agent)
FIG. 7 is a sectional view showing an embodiment of a fire extinguishing apparatus containing a powder fire extinguisher together with a lithium ion battery. As shown in FIG. 7, the fire extinguisher 12 according to the present embodiment houses a powder fire extinguisher 40 between the fire extinguishing metal nets 30 a and 30 b housed in the housing 18. The powder fire extinguisher 40 is filled in a sealed bag 42 such as a plastic bag that melts or burns by receiving heat from the flame of the electrolyte sprayed by the operation of the safety valve 14 of the lithium ion battery 10, and absorbs moisture during use. It does not solidify or deteriorate.

  FIG. 8 is an explanatory view showing the operation of the fire extinguishing apparatus of FIG. As shown in FIG. 8, suppose that during aging, the lithium-ion battery 10 causes a thermal runaway, the safety valve 14 is activated (exploded), and the filled electrolyte ignites and a fire that blows out a flame violently occurs. The flame of the electrolyte sprayed from the safety valve 14 enters the flame extinguishing metal mesh 30a provided in the fire extinguishing apparatus 12, and the flame is suppressed while passing through the flame extinguishing metal mesh 30a. The powder fire extinguisher 40 filled inside is released, the flame of the electrolyte solution disappears by entering the flame extinguishing metal mesh 30b while entraining the powder extinguisher 40, and further the fog that has passed through the flame extinguishing metal mesh 30a, 30b The fine particles of the electrolyte in the activated state enter the adsorption filter 34 using glass wool and are adsorbed and held, and suppress the flame and the injection of the electrolyte from the discharge port 28 to the outside.

(Lithium ion battery fire extinguishing device with safety valve on the side)
FIG. 9 shows the appearance of a fire extinguisher mounted on a rectangular lithium ion battery provided with a safety valve on the side, in a plan view (FIG. 9A), a front view (FIG. 9B), and a side view (FIG. 9C). FIG. 10 is a plan sectional view (FIG. 10A), a longitudinal section (FIG. 10B), and a transverse section (FIG. 10C) of the fire extinguishing apparatus of FIG. 9 mounted on a lithium ion battery. FIG. 11 is an explanatory view showing an assembled and disassembled state of the fire extinguisher of FIG. 9 with respect to the lithium ion battery.

  As shown in FIGS. 9, 10, and 11, the lithium ion battery 10 targeted by the present embodiment is provided with a safety valve 14 on a side surface. For this reason, the fire extinguisher 12 includes a casing 18 having a vertically long sealed box structure that covers the periphery of the safety valve 14 provided on the side of the battery, and a holding portion 20 is integrally formed on the left side of the upper portion of the casing 18 in the figure.

  The holding part 20 is formed with a pressing part 20a bent inward at the skirt-shaped tip, and when inserted into the lithium ion battery 10 from above, the side of the battery outer container is sandwiched by the pressing part 20a to be attached in a predetermined manner. Strength can be secured. In addition, a rectangular opening 22 is formed on the upper end surface of the hold unit 20 in order to expose the electrode terminals 16a and 16b of the lithium ion battery 10 to the outside.

  The housing 18 arranged on the right side of the lithium ion battery 10 in the drawing by the holding unit 20 forms an opening 64 relative to the safety valve 14 of the lithium ion battery 10, and extinguishes flames above and below the empty space inside the opening 64. The metal nets 30a and 30a, the powder fire extinguishing agents 40a and 40b filled in the airtight bag 42, and the adsorption filters 34a and 34b are sequentially arranged, and a plurality of discharge ports 28 are provided in the partition wall outside the adsorption filters 34a and 34b. The mesh structure of the flame extinguishing metal nets 30a and 30b is the same as that of the embodiment of FIGS. 1 to 6, and the adsorption filters 34a and 34b are made of glass wool, which is heat resistant fiber. Agents 40a and 40b are the same as in the embodiment of FIG.

  In addition, a heat sensing cable 38 that functions as a fire sensor unit that detects heat from the flame of the electrolyte sprayed by the operation of the safety valve 14 of the lithium ion battery 10 is provided inside the housing 18. Is connected to the connector 36 provided on the side of the housing 18 at one end of two signal lines, and covers the safety valve 14 via the adsorption filter 34b, the side of the sealed bag 42 of the powder extinguishing agent 40b, and the flame extinguishing metal mesh 30b. It is arranged at a position where it is drawn out into the space and directly receives the flame of the electrolytic solution ejected from the safety valve 14.

  FIG. 12 is an explanatory view showing the operation of the fire extinguishing apparatus when the electrolyte solution is ejected due to thermal runaway of the lithium ion battery. If the lithium ion battery 10 causes a thermal runaway and the safety valve 14 is activated (ruptures), and the electrolyte that has been filled ignites and causes a fire to blow out the flame violently, the flame of the electrolyte that is ejected from the safety valve 14 is The flame enters the casing 18 through the opening 64 of the fire extinguishing device 12 and is shut off while passing through the flame extinguishing metal nets 30a and 30b. Subsequently, the flame strikes the sealing bag 42 to melt it and fill the inside. The powder extinguisher 40a, 40b is released, the electrolyte flame disappears while entraining the powder extinguisher 40a, 40b, and the fine particles of the electrolyte in the atomized state after the flame disappears are adsorbed filter 34a using glass wool. 34b is adsorbed and greatly suppresses the flame and electrolyte from the outlet 28 to the outside.

(Fire extinguishing device for cylindrical lithium-ion battery)
FIG. 13 is an explanatory view showing a fire extinguishing apparatus attached to a cylindrical lithium ion battery in a front cross-section (FIG. 13A) and a plane (FIG. 13C).

  As shown in FIG. 13, the lithium ion battery 10 targeted by the present embodiment stores an electrode body together with an electrolytic solution in a cylindrical outer container formed of, for example, aluminum or an aluminum alloy. The electrode body of the lithium ion battery 100 is formed in a cylindrical shape, for example, by winding a positive electrode plate and a negative electrode plate in a spiral shape with a separator interposed therebetween.

An electrode terminal 116a serving as a positive electrode is provided at the upper end of the outer casing of the lithium ion battery 100, and an electrode terminal (not shown) serving as a negative electrode is provided at the bottom. A safety valve 114 is provided in the electrode terminal 116 a at the top of the lithium ion battery 100. The safety valve 114 has an opening provided in the outer container closed with a thin aluminum plate, or a portion of the safety valve 114 is processed into a thin wall, and an X-shaped groove is formed as necessary. When increased, it operates (ruptures) at a predetermined pressure to prevent the outer container from bursting.

  Here, the outer size of the lithium ion battery 100 is, for example, about (diameter R = 80 mm to 120 mm) × (height H = 80 mm to 120 mm) when used for an electric vehicle, for example.

  The lithium ion battery 100 is used by being stored in a power storage device known as a battery module or a battery pack. In the case of an electric vehicle, for example, 24 batteries are stored in a storage container and connected in series. When the average cell voltage of the lithium ion battery 100 is, for example, 3.5 volts, the voltage of the positive output terminal and the negative output terminal of the power storage device is 84 volts by connecting 24 in series. Also in this case, the number of lithium ion batteries 100 housed in the power storage device is a number corresponding to the required voltage.

  The fire extinguisher 112 includes a cap-shaped housing 118 that covers the periphery of the safety valve 114 provided on the upper end surface, and a holding portion 120 is integrally formed at the lower portion of the housing 118.

  The holding part 120 has a fitting part 120a formed by drawing or the like in the middle. When the holding part 120 is inserted into the lithium ion battery 100 from above, the fitting part 120a is fitted into the sealing throttle part 102 of the outer container, The mounting strength can be secured.

  In the casing 118 of the fire extinguishing device 112, a flame extinguishing metal net 130 and an adsorption filter 134 are sequentially arranged through an empty space that covers the safety valve 114, and a plurality of exhausts are disposed on the upper end surface and upper side surface that are outside the adsorption filter 134. An outlet 128 is provided. In addition, the flame-extinguishing metal mesh 130 and the adsorption filter 134 are the same as those in the embodiment of FIGS.

  In addition, a heat sensing cable 138 that functions as a fire sensor unit that detects heat generated by the flame of the electrolyte sprayed by the operation of the safety valve 114 of the lithium ion battery 100 is provided inside the housing 118, and the heat sensing cable 138 is provided. One end of two signal lines is connected to a connector 136 provided on the upper end surface of the housing 118, drawn out to an empty space covering the safety valve 114 through the adsorption filter 134 and the flame extinguishing metal net 130, and the electrolyte discharged from the safety valve 114 It is placed in a position to receive the flame directly.

  FIG. 14 is an explanatory view showing the operation of the fire extinguishing apparatus when the electrolyte solution is ejected due to thermal runaway of the lithium ion battery.

  In the aging process of the lithium ion battery, after the lithium ion battery 100 is assembled, initial charging (full charge to SOC 100%) is performed, and then, as shown in FIG. 4 are arranged in the aging container 44 in the same manner as shown in FIG. 4, for example, the plug 37 of the signal line 45 is connected to the connector 136 of the lithium ion battery 100, and the signal is sent to the fire detection circuit unit 46 provided in the aging container 44. Connect line 45 to allow fire monitoring.

  If the lithium-ion battery 100 undergoes thermal runaway during aging and the safety valve 114 is actuated (ruptured), and the filled electrolyte ignites to cause a fire that blows out a flame violently, the electrolysis ejected from the safety valve 114 The liquid flame enters the casing 118 of the fire extinguishing apparatus 100 and disappears while passing through the fire extinguishing metal net 130. The fine particles of the electrolyte solution that has been atomized and disappeared from the flame are made of glass wool. The adsorbed filter 134 is used and adsorbed, and the flame and electrolyte are prevented from being ejected from the discharge port 128 to the outside.

(Embodiment of fire extinguishing apparatus provided with powder fire extinguishing agent)
FIG. 15 is a sectional view showing an embodiment of a fire extinguisher containing a powder fire extinguisher together with a cylindrical lithium ion battery. As shown in FIG. 15, the fire extinguisher 112 according to the present embodiment stores the fire extinguishing metal nets 130 a and 130 a divided into two in the housing 118, and stores the powder fire extinguishing agent 140 therebetween. The powder fire extinguisher 140 is filled in a sealed bag 142 such as a plastic bag that melts or burns by receiving heat from the flame of the electrolyte sprayed by the operation of the safety valve 114 of the lithium ion 100, and absorbs moisture during use to solidify. To prevent or deteriorate.

  The fire extinguisher 112 according to the present embodiment is a safety valve when the lithium ion battery 100 causes a thermal runaway and the safety valve 114 is activated (exploded), and the filled electrolyte is ignited to cause a fire to blow out a flame violently. The flame of the electrolyte sprayed from 114 enters the flame extinguishing metal mesh 130a provided in the fire extinguishing apparatus 100, the flame is suppressed while passing through the flame extinguishing metal mesh 130a, and the flame hits the sealing bag 142 to melt it. The powder fire extinguisher 140 filled inside is released, and the flame of the electrolyte disappears by entering the fire extinguishing metal net 130b while entraining the powder fire extinguisher 140, and is further in an atomized state passing through the fire extinguishing metal net 130b. The fine particles of the electrolyte enter the adsorption filter 134 using glass wool and are adsorbed and held, and suppress the flame from the discharge port 128 to the outside and the ejection of the electrolyte.

(Embodiment of fire extinguishing apparatus with electrode lead-out structure)
FIG. 16 is a cross-sectional view showing an embodiment of a fire extinguishing apparatus provided with an electrode extraction structure together with a lithium ion battery. FIG. 16 (A) shows a front cross-section, and FIG.

  The fire extinguishing apparatus 112 shown in FIG. 13 has the battery electrode terminal 116a housed in the casing 118 of the fire extinguishing apparatus 112, and it is necessary to remove the fire extinguishing apparatus 112 when measuring the battery voltage associated with aging. ,It takes time and effort.

  Therefore, in the embodiment of FIG. 16, the electrode lead member 180 is provided in the fire extinguisher 112 as an electrode lead-out structure that is in electrical contact with the electrode terminal 116 a of the cylindrical lithium ion battery 100 and pulls out to the outside. The electrode lead member 180 forms a contact portion 184 having a lower portion bent in an inverted L shape to form an opening hole 186 that opens the relative position of the safety valve 114, and a tip is bent outward from the upper portion to take out the electrode terminal portion 188. ing.

  Further, since the casing 118 of the fire extinguishing device 112 is made of a conductive metal, an insulating coating 182 is provided in the middle of the electrode lead member 180 so as not to make electrical contact.

  Thus, by taking out one electrode terminal 116a of the lithium ion battery 100 with the electrode lead member 180 provided in the fire extinguishing device 112, it is possible to measure the battery voltage, charge and discharge, etc. without removing the fire extinguishing device 112. And

[Modification of the present invention]
(Single cell)
In the above embodiment, a lithium ion battery is taken as an example of a unit cell, but the present invention is not limited to this, and includes an appropriate non-aqueous electrolyte secondary battery using a flammable electrolyte.

(Use of fire extinguishing equipment)
The above embodiment is an example in which a fire extinguishing device is attached to a lithium ion battery in a production process such as an aging process, but a fire extinguishing device is also attached to a power storage device containing a plurality of lithium ion batteries. In this state, the lithium ion battery may be stored in a storage container and connected in series with a bus bar (electrode connection bar). When a lithium ion battery equipped with a fire extinguishing device is stored in a power storage device, a fire extinguishing device having a structure in which the electrode terminal of the lithium ion battery is exposed to the outside is used.

(Fire detection part)
In the above embodiment, a heat detection cable is provided as a fire detection unit for detecting a fire due to an abnormality of the lithium ion battery. In addition to this, a temperature sensor such as a thermocouple or a thermistor, laser pulse light is incident. An appropriate fire detection unit such as an optical fiber sensor for measuring the temperature from the intensity of the backscattered light may be provided.

(Use of lithium ion battery)
Moreover, although said embodiment took the lithium ion battery for aircrafts and electric vehicles as an example, it can provide similarly as a fire extinguishing apparatus of the lithium ion battery for houses, and also other suitably The same applies to lithium-ion batteries installed in equipment, devices, equipment, and facilities.

(Other)
The present invention is not limited to the above-described embodiment, includes appropriate modifications without impairing the object and advantages thereof, and is not limited by the numerical values shown in the above-described embodiment.

10, 100: Lithium ion battery 12, 112: Fire extinguishing device 14, 114: Safety valve 16a, 16b, 116a: Electrode terminal 18, 118: Housing 20, 120: Hold part 28, 128: Discharge port 30a, 30b, 130a, 130b: Extinguishing metal mesh 34, 34a, 34b, 134: Adsorption filter 36, 136: Connector 38, 138: Thermal sensing cable 40: Powder extinguisher 42: Sealing bag 44: Aging container 46: Fire detection circuit unit 180: Electrode lead Element

Claims (8)

In a fire extinguisher attached to a single cell equipped with a safety valve that opens when the internal pressure rises in the battery outer container,
A housing that covers the outside of the safety valve and is detachably attached to the battery outer container, and has a discharge port formed at an outer position away from the safety valve;
An extinguishing metal net disposed on the safety valve side in the housing, and extinguishing the flame of the electrolyte sprayed by the operation of the safety valve of the unit cell;
An adsorption filter using a heat-resistant fiber that is disposed in the housing following the flame-extinguishing metal net and adsorbs and holds the electrolyte that has passed through the flame-extinguishing metal net;
A fire extinguisher characterized by comprising:   2. The fire extinguishing apparatus according to claim 1, wherein the fire extinguishing metal mesh has a mesh structure in which the mesh size decreases from the receiving side of the electrolyte flame toward the depth direction.   The fire extinguishing apparatus according to claim 1, wherein the heat-resistant fiber of the adsorption filter is glass wool.   The fire extinguisher according to claim 1, wherein a powder fire extinguisher is stored in the casing.   5. The fire extinguishing apparatus according to claim 4, wherein the powder fire extinguisher is filled in a sealed bag that is melted or destroyed by receiving heat from the flame of an electrolyte sprayed by operation of a safety valve of the unit cell. A fire extinguishing apparatus, characterized in that a sealed bag filled with a fire extinguishing agent is disposed at the front, inside, or rear of the flame extinguishing metal mesh. The fire extinguishing apparatus according to claim 1, further comprising:
A fire sensor unit that is provided in the case and detects heat generated by the flame of the electrolyte sprayed by the operation of the safety valve of the unit cell and outputs a detection signal;
A fire detection circuit for detecting a fire based on the detection signal output from the sensor means and outputting a fire detection signal;
A fire extinguishing device characterized by being provided. The fire extinguishing apparatus according to claim 6,
The fire sensor unit is a heat-sensing cable that detects a fire by bringing a pair of signal wires into contact with a short circuit state by melting the insulating coating when receiving heat from a flame,
Laying the heat sensing cable through the housing opposite the safety valve and connecting it to a connector provided in the housing;
The fire extinguishing apparatus, wherein the heat sensing cable is connected to the fire detection unit provided outside the housing via the connector.   2. The fire extinguishing apparatus according to claim 1, further comprising an electrode lead member having one end in contact with the electrode terminal of the unit cell and the other end taken out of the casing, and the casing is disposed in the middle of the electrode lead member. A fire extinguishing apparatus provided with an insulating coating that prevents contact with a body.

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