JP2009099305A - Power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To greatly improve safety in an abnormal condition by surely preventing nonaqueous electrolyte batteries from becoming abnormally high temperatures to be fired while efficiently cooling the nonaqueous electrolyte batteries. <P>SOLUTION: The power supply device comprises the plurality of chargeable nonaqueous electrolyte batteries stored in an exterior case 2. Herein, fire extinguishing chemical 3 is filled in the exterior case 2, and the nonaqueous electrolyte batteries 1 are immersed in the fire extinguishing chemical 3 and cooled via the fire extinguishing chemical 3. The nonaqueous electrolyte batteries immersed in the fire extinguishing chemical are cooled in an ideal condition to reduce their temperature rise. This surely prevents the nonaqueous electrolyte batteries from becoming abnormally high temperatures to be fired. When the nonaqueous electrolyte batteries become the abnormally high temperatures to release high temperature gas, the gas is released into the fire extinguishing chemical, thereby surely preventing cooling liquid from catching fire from the gas as well as firing the outside resulting therefrom. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply device in which a plurality of nonaqueous electrolyte batteries are housed in an outer case, and more particularly to a power supply device that can prevent fire due to thermal runaway of a nonaqueous electrolyte battery and improve safety.

  A non-aqueous electrolyte battery such as a lithium ion battery may spread to other cells and cause a thermal runaway due to various causes such as an internal short circuit or overcharge. In particular, when a lithium ion battery runs out of heat, the temperature of the battery rises remarkably and may become 300 ° C. to 400 ° C. or higher, causing ignition. In a power supply device for a vehicle equipped with a large number of batteries, when a plurality of batteries cause a thermal runaway, the energy of the thermal runaway becomes extremely large and causes ignition.

In order to prevent ignition due to overheating of the battery, an inert substance such as an inert gas is filled in the sealed case, or an inert gas generating substance or a fire extinguisher is built in the case, or the battery is installed. Devices that have been immersed in non-flammable refrigerants have been developed. (See Patent Documents 1 to 4)
Japanese Patent Laid-Open No. 10-247527 JP-A-10-55822 JP 2001-332237 A Japanese Patent Laid-Open No. 11-40211

  The power supply device described in Patent Document 1 stores a plurality of batteries and a fire extinguisher together in a case. This power supply unit depresses the lever that is the starting operation means of abnormal heat generation reduction means such as a fire extinguisher or detects this electrically when the battery heats up abnormally and the temperature in the case exceeds the allowable value. Then, the lever is automatically pushed down, and the powder containing sodium hydrogen carbonate as a main component is released into the housing by the gas pressure of carbon dioxide. Sodium bicarbonate absorbs heat when heated to a high temperature, generating carbon dioxide and water vapor, lowering the temperature inside the housing, keeping it in an inert atmosphere, preventing the occurrence of fire, and terminating the combustion reaction .

  Patent Document 2 discloses a case in which a plurality of batteries are housed in a case, and an inert gas such as nitrogen, helium, argon, neon, krypton, xenon, carbon dioxide, or nonflammable non-water is contained in the case. A power supply device that is filled with a solvent or a liquid, gel, or solid polymer and that has a sealed case is described. With this structure, even if the battery is in an abnormal state and gas is injected into the case, the battery is surrounded by an inactive substance, reducing the danger of the power supply becoming dangerous There is a feature that can be.

  Furthermore, the power supply device described in Patent Document 3 houses a plurality of batteries in a case, and generates an inert gas by pyrolysis in the case. Sodium azide, potassium hydrogen carbonate, sodium hydrogen carbonate, potassium carbonate Contains sodium carbonate. These are thermally decomposed to generate incombustible gases such as nitrogen, water vapor, and carbon dioxide. In this power supply device, when a battery stored in the case abnormally generates heat, the inert gas generating substance is thermally decomposed to generate an inert gas in the case. Therefore, when the battery is overheated, it is possible to fill the inert gas around the battery and prevent ignition.

  The above power supply cannot efficiently cool a battery whose temperature rises. In addition, if the mechanism for detecting the abnormal temperature of the battery fails, there is a drawback that the heat generation of the battery cannot be reliably prevented. A power supply apparatus that efficiently cools a battery is described in Patent Document 4. In this power supply device, the battery is immersed in a nonflammable low boiling point refrigerant. Since a refrigerant such as Fluorinert is used as the nonflammable low-boiling point refrigerant, when the battery safety valve is opened and high-temperature gas is released into the refrigerant, ignition of the refrigerant by the high-temperature gas can be prevented. However, it cannot be prevented that the temperature of the battery becomes abnormally high and a high-temperature gas is released, which leaks outside and ignites.

  The present invention has been developed for the purpose of solving the above drawbacks of the conventional power supply apparatus. An important object of the present invention is to provide a power supply capable of significantly improving safety in an abnormal state by reliably preventing the nonaqueous electrolyte battery from firing at an abnormally high temperature while efficiently cooling the nonaqueous electrolyte battery. To provide an apparatus.

The power supply device of the present invention has the following configuration in order to achieve the above-described object.
The power supply device houses a plurality of nonaqueous electrolyte batteries 1 that can be charged in an outer case 2. In the power supply device, the extinguishing case 2 is filled with the extinguishing chemical solution 3, and the nonaqueous electrolyte battery 1 is immersed in the extinguishing chemical solution 3, and the nonaqueous electrolyte battery 1 is liquid-cooled through the extinguishing chemical solution 3.

  In the power supply device according to claim 2 of the present invention, the fire extinguishing liquid 3 is either perfluorocarbon or hydrofluoroether.

  In the power supply device according to claim 3 of the present invention, the nonaqueous electrolyte battery 1 is a lithium ion battery.

  In the power supply device according to claim 4 of the present invention, the outer case 2 is a metal case, and the outer case 2 of the metal case radiates the heat of the nonaqueous electrolyte battery 1 to the outside through the extinguishing chemical solution 3.

  The power supply device according to claim 5 of the present invention includes a heat pipe 21 inserted into the exterior case 2 and a heat sink 22 connected to the heat pipe 21 and disposed outside the exterior case 2. 22 radiates the heat of the nonaqueous electrolyte battery 1 to the outside through the heat pipe 21 and the extinguishing liquid 3.

  The power supply device of the present invention is characterized in that it can prevent the ignition at an abnormally high temperature while efficiently cooling the non-aqueous electrolyte battery, and can significantly improve the safety in the abnormal state. This is because the power supply device of the present invention immerses the nonaqueous electrolyte battery in the extinguishing chemical solution and cools it through the extinguishing chemical solution. The structure in which the nonaqueous electrolyte battery is immersed in the fire extinguishing liquid is cooled in an ideal state because the nonaqueous electrolyte battery is liquid cooled. That is, the heat generated by the non-aqueous electrolyte battery is conducted to a fire extinguisher solution that is thermally bonded in an ideal state over a wide area. For this reason, the fire extinguisher liquid cools the nonaqueous electrolyte battery in an ideal state. Therefore, the temperature rise of the nonaqueous electrolyte battery can be reduced. Moreover, since the nonaqueous electrolyte battery is immersed in the fire extinguishing agent solution, the nonaqueous electrolyte battery can be reliably prevented from igniting at an abnormally high temperature. Furthermore, when the non-aqueous electrolyte battery becomes abnormally hot and releases a high-temperature gas, the gas is released into the extinguishing liquid, which not only ignites the coolant caused by the gas but also ignites externally. Can be surely prevented.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a power supply device for embodying the technical idea of the present invention, and the present invention does not specify the power supply device as follows.

  Further, in this specification, for easy understanding of the scope of claims, numbers corresponding to the members shown in the embodiments are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  The power supply device shown in FIGS. 1 to 3 includes a plurality of nonaqueous electrolyte batteries 1 that can be charged and an exterior case 2 that houses the nonaqueous electrolyte battery 1. The exterior case 2 is filled with a fire extinguishing chemical solution 3. Thus, the nonaqueous electrolyte battery 1 is immersed in the extinguishing agent solution 3. This power supply device liquid-cools the nonaqueous electrolyte battery 1 via the extinguishing agent solution 3. The nonaqueous electrolyte battery 1 is a lithium ion battery. However, the present invention does not specify a non-aqueous electrolyte battery as a lithium ion battery. As the non-aqueous electrolyte battery, other rechargeable batteries using an electrolytic solution as a non-aqueous electrolyte can be used. In the illustrated power supply apparatus, the nonaqueous electrolyte battery is a cylindrical battery, but a square battery can also be used as the nonaqueous electrolyte battery.

  In the illustrated power supply apparatus, a plurality of nonaqueous electrolyte batteries 1 are housed in an outer case 2 as a battery assembly 10. The battery assembly 10 has a plurality of non-aqueous electrolyte batteries 1 arranged in a parallel and close attitude with a plastic battery holder 4 which is an insulating material. The battery holder 4 is integrally formed with a plurality of holding cylinders 5 for inserting the nonaqueous electrolyte battery 1 and holding it in a fixed position. The nonaqueous electrolyte battery 1 is inserted into the holding cylinder 5 and fixed. Placed in position. The holding cylinder 5 is open at both ends, and exposes the end of the nonaqueous electrolyte battery 1 from the opening at the end. A lead plate 6 is disposed on the exposed portion, and the lead plate 6 is welded to the end face electrode of the nonaqueous electrolyte battery 1. In the illustrated battery assembly 10, lead plates 6 are arranged on both surfaces of a battery holder 4, and adjacent nonaqueous electrolyte batteries 1 are connected in series and in parallel with the lead plates 6. The nonaqueous electrolyte battery 1 whose both ends are welded to the lead plate 6 is arranged so as not to come out of the holding cylinder 5.

  The battery holder 4 has a gap between the holding cylinders 5. In the battery assembly 10, the extinguishing chemical 3 enters the gap between the holding cylinders 5 and cools the nonaqueous electrolyte battery 1 through the holding cylinders 5. The holding cylinder 5 covers the entire circumference of the nonaqueous electrolyte battery 1, or an opening is provided in a part thereof so that a part of the surface of the nonaqueous electrolyte battery 1 is brought into direct contact with the extinguishing agent solution 3. The battery holder 4 in which the holding cylinder 5 covers the entire circumference of the nonaqueous electrolyte battery 1 can more reliably prevent induction of thermal runaway of the nonaqueous electrolyte battery 1. In addition, the structure in which an opening is provided in a part of the holding cylinder 5 and a part of the surface of the nonaqueous electrolyte battery 1 is brought into direct contact with the extinguishing chemical solution 3 efficiently cools the nonaqueous electrolyte battery 1 with the extinguishing chemical solution 3. it can. In addition, a holding | maintenance cylinder can also be eliminated and, thereby, a nonaqueous electrolyte battery can be efficiently cooled with a digestive liquid. In addition, when the holding cylinder is eliminated, a sheet-like separator (battery having a function of allowing liquid to pass between the batteries in order to maintain insulation and stably arrange the nonaqueous electrolyte battery as necessary. The separator utilized in the secondary battery including can also be used.

  The entire battery assembly 10 is immersed in the fire extinguishing liquid 3. In the battery assembly 10 immersed in the extinguishing agent solution 3, the extinguishing agent solution 3 enters the gap. In this state, the nonaqueous electrolyte battery 1 is cooled through the holding cylinder 5 or directly in contact with the extinguishing liquid 3. In addition, since the lead plate 6 is also immersed in the fire extinguishing agent solution 3, the nonaqueous electrolyte battery 1 is cooled by the extinguishing agent solution 3 through the lead plate 6.

  Although not shown, the nonaqueous electrolyte battery 1 is provided with an opening of a safety valve at the end. The safety valve opens when the internal pressure becomes higher than the set pressure. When the non-aqueous electrolyte battery 1 becomes abnormally used and the internal pressure increases, the temperature also increases. Accordingly, high-temperature gas is released from the safety valve that opens. Since the non-aqueous electrolyte battery 1 is immersed in the fire extinguisher liquid 3, the gas released to the outside of the battery is released into the fire extinguisher liquid 3. Therefore, the released gas does not ignite.

  Further, in the illustrated power supply apparatus, the middle case 8 is fixed to the battery holder 4 via the gasket 7. The middle case 8 is fixed to one surface of the battery holder 4, the upper surface in the figure. A circuit board 9 is mounted on the middle case 8. The circuit board 9 is mounted with an electronic component (not shown) that realizes a protection circuit for the nonaqueous electrolyte battery 1 constituting the battery assembly 10. The protection circuit mounted on the circuit board 9 detects the voltage of each nonaqueous electrolyte battery 1 and also detects the temperature to control the charge / discharge current. For example, when the voltage of any non-aqueous electrolyte battery 1 is increased to the maximum voltage, charging is stopped, and when the battery voltage is lower than the minimum voltage, discharging is stopped to protect the non-aqueous electrolyte battery 1. Further, the protection circuit detects the temperature of the battery or the extinguishing liquid 3, and controls the charge / discharge current based on the temperature of the battery. This protection circuit protects the battery by limiting or shutting off the charge / discharge current when the temperature of the battery or the extinguishing liquid 3 becomes higher than the set maximum temperature or becomes lower than the set minimum temperature.

  The middle case 8 has a box shape that opens upward, the opening is closed by the upper case 11, and the circuit board 9 is accommodated therein. The structure in which the middle case 8 is sealed with the upper case 11 can prevent the extinguishing liquid 3 from entering the inside. However, since an insulating liquid is used for the fire extinguisher liquid, it is possible to fill the middle case with the fire extinguishing liquid.

  The outer case 2 has a box shape that opens upward and closes the bottom, and the upper opening is sealed with an upper case 11 via a gasket 7. The outer case 2 is a metal case such as aluminum. The metal case is excellent in heat conduction, and effectively dissipates the heat of the nonaqueous electrolyte battery 1 to the outside through the filled extinguishing liquid 3. Furthermore, the exterior case 2 shown in the figure has a structure in which convex discharge fins 12 extending vertically are provided on the surface to increase the discharge area and effectively radiate heat.

  Further, a power supply device having an excellent heat dissipation effect is shown in FIGS. In this power supply device, a heat pipe 21 is inserted in the outer case 2. The heat pipe 21 is inserted between the battery assembly 10 and the outer case 2 so as to be insulated from the battery assembly 10. The heat pipe 21 is connected to a heat sink 22 disposed outside the exterior case 2. FIG. 5 shows a structure for connecting the heat pipe 21 to the heat sink 22. The heat sink 22 connects a plurality of heat pipes 21. As shown in FIG. 4, the heat sink 22 is disposed outside the upper case 11. In this power supply device, the heat of the fire extinguishing liquid 3 is efficiently conducted to the heat sink 22 by the heat pipe 21 and radiated. Therefore, this power supply device can effectively dissipate the ignition of the nonaqueous electrolyte battery 1 through the heat pipe 21 and the extinguishing chemical 3.

  The exterior case 2 in FIG. 2 accommodates the battery assembly 10 via a cushion sheet 13. The cushion sheet 13 is a sheet that deforms and absorbs an impact, and is a rubber-like elastic body, a plastic foam, a soft plastic sheet, or the like. The cushion sheet 13 is disposed between the outer case 2 and the battery assembly 10 to absorb an impact applied to the outer case 2 and prevent a failure due to the impact of the battery assembly 10. In the power supply device of FIG. 2, cushion sheets 13 are disposed on both end surfaces and upper and lower surfaces of the battery assembly 10. Further, an insulating sheet 14 is disposed between the lead plate 6 of the battery assembly 10 and the inner surface of the outer case 2 that is a metal case to prevent the lead plate 6 from contacting the outer case 2. However, in the battery assembly in which a protrusion is provided along the outer peripheral edge of the battery holder and the lead plate is disposed inside the protrusion, the lead plate contacts the inner surface of the outer case without using an insulating sheet. Can be prevented.

  The outer case 2 is filled with a fire extinguishing liquid 3 and accommodates the battery assembly 10 and is sealed. The sealed outer case 2 immerses the battery assembly 10 in the extinguishing chemical solution 3 and immerses the nonaqueous electrolyte battery 1 of the battery assembly 10 in the extinguishing chemical solution 3. The fire extinguishing liquid 3 is an insulating fire extinguishing liquid 3, and perfluorocarbon, hydrofluoroether, Novec 1230 fire extinguishing liquid, or the like can be used.

The following power supply device is prototyped, and the temperature of the nonaqueous electrolyte battery is measured as follows.
The exterior case of the power supply device is made of aluminum and has a size of 87 mm × 186 mm × 336 mm and a volume of about 5.4 liters. The battery assembly housed in the outer case includes 15 sets of 15 lithium ion batteries connected in series, and includes 120 non-aqueous electrolyte batteries in total. The outer case is filled with 31.33 liters of a fire extinguisher liquid having a boiling point of 165 ° C. to 185 ° C., a specific heat of 1 J / kg, and a specific gravity of 1.9.

  When this power supply is discharged at 50 A at an environmental temperature of 40 ° C. for about 20 minutes, the temperature rise is about 23 ° C. On the other hand, the temperature rise without filling the extinguishing liquid is about 40 ° C., which is twice as large. From this, it becomes clear that the power supply device of the present invention is extremely effectively cooled by immersing the non-aqueous electrolyte battery in a fire extinguisher solution. In addition, since the nonaqueous electrolyte battery is immersed in a fire extinguisher solution, even if the nonaqueous electrolyte battery is charged / discharged in an abnormal state and thermal runaway occurs, the fire extinguisher solution is efficiently cooled with liquid and the induction of thermal runaway is effective. Is prevented. Furthermore, even if a high-temperature gas is released from the nonaqueous electrolyte battery, it can be reliably prevented from igniting by the extinguishing chemical solution.

It is a perspective view of the power supply device concerning one Example of this invention. It is a disassembled perspective view of the power supply device shown in FIG. It is a schematic sectional drawing of the power supply device concerning one Example of this invention. It is a perspective view of the power supply device concerning the other Example of this invention. It is a perspective view which shows the structure which connects the heat pipe of the power supply device shown in FIG. 4 to a heat sink. It is a schematic sectional drawing of the power supply device concerning the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Non-aqueous electrolyte battery 2 ... Exterior case 3 ... Extinguishing agent solution 4 ... Battery holder 5 ... Holding cylinder 6 ... Lead plate 7 ... Gasket 8 ... Middle case 9 ... Circuit board 10 ... Battery assembly 11 ... Upper case 12 ... Radiation fin 13 ... Cushion sheet 14 ... Insulating sheet 21 ... Heat pipe 22 ... Heat sink

Claims (5)

  A power supply device in which a plurality of nonaqueous electrolyte batteries (1) that can be charged are housed in an outer case (2), the outer case (2) is filled with a fire extinguishing chemical (3), and this fire extinguishing chemical ( A power supply device in which the nonaqueous electrolyte battery (1) is immersed in 3) and the nonaqueous electrolyte battery (1) is liquid-cooled via the fire extinguishing liquid (3).   The power supply device according to claim 1, wherein the fire extinguishing liquid (3) is one of perfluorocarbon and hydrofluoroether.   The power supply apparatus according to claim 1, wherein the nonaqueous electrolyte battery (1) is a lithium ion battery.   The outer case (2) is a metal case, and the outer case (2) of the metal case dissipates the heat of the nonaqueous electrolyte battery (1) to the outside through the fire extinguishing liquid (3). Power supply device described in 1.   A heat pipe (21) inserted into the outer case (2); and a heat sink (22) connected to the heat pipe (21) and disposed outside the outer case (2). The power supply device according to claim 1, wherein (22) dissipates heat of the nonaqueous electrolyte battery (1) to the outside through the heat pipe (21) and the fire extinguishing liquid (3).

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