WO2012014348A1

WO2012014348A1 - Cell module and cell pack

Info

Publication number: WO2012014348A1
Application number: PCT/JP2011/001411
Authority: WO
Inventors: 青木知昌; 安井俊介; 下司真也; 藤川万郷; 岸井大輔
Original assignee: パナソニック株式会社
Priority date: 2010-07-28
Filing date: 2011-03-10
Publication date: 2012-02-02

Abstract

Provided is a cell module which has a reduced risk of catching fire or ignition by causing an inert fluid to rapidly and accurately act on the interior of a cell housing case when the abnormality of a unit cell occurs. The cell module is provided with a plurality of unit cells (100), a cell housing case (200) having a chamber that houses the plurality of unit cells (100), a fluid introduction port (120) for introducing an inert fluid into the chamber when the abnormality of a unit cell occurs, and a gas discharge port (130) for discharging, from within the chamber, combustible gas generated from the unit cell when the abnormality of the unit cell occurs. In the cell housing case (200), a pressure sensor (150) for detecting the internal pressure is provided. An inert fluid supply control means (151) introduces the inert fluid from the fluid introduction port (120) on the basis of the result of the detection by the pressure sensor (150).

Description

Battery module and battery pack

The present invention relates to a battery module and a battery pack used for an electric vehicle or the like, and more particularly, to electrically connect a battery module containing a secondary battery using a non-aqueous electrolyte typified by a lithium ion battery or the like and a plurality of battery modules. The battery pack connected to.

In recent years, non-aqueous secondary batteries, in particular lithium ion secondary batteries, have features such as light weight, high electromotive force, and high energy density. Therefore, mobile phones, digital cameras, video cameras, notebooks, etc. As a power source for driving various types of portable electronic devices such as personal computers and mobile communication devices, demand is increasing.

On the other hand, in order to reduce the amount of fossil fuel used and the amount of CO ₂ emission, battery modules capable of obtaining desired voltages and capacities by combination have been developed as power sources for driving motors of automobiles and the like. .

This battery module needs to improve safety against abnormal situations such as automobile collision. For example, as shown in Patent Document 1, an inert fluid such as a fire extinguisher is used in order to prevent battery smoke and ignition when abnormal. It is designed to be injected into the unit cell.

By the way, for example, in Patent Document 2, a sealed container containing a fire extinguisher is installed in a chamber containing a battery module, and when the abnormality occurs, the sealed container is destroyed and the fire extinguisher acts on the unit cell. Things are listed.

JP 2009-207650 A JP 2007-200800 A

However, in the technique of Patent Document 2 described above, the inert fluid (extinguishing agent) is less likely to act on the unit cell due to the presence of combustible gas generated from the unit cell when an abnormality occurs than in the technique of Patent Document 1, so There is a problem that it is difficult to reduce the risk.

The present invention has been made in view of such problems, and provides a battery module that can reduce the risk of firing or firing when an abnormality occurs in a unit cell, and a battery pack in which a plurality of the battery modules are connected. Objective.

A battery module according to the present invention includes a plurality of unit cells, a battery storage case having a chamber for storing the plurality of unit cells, and an opening that opens to the battery storage case, and provides an inert fluid when an abnormality occurs in the unit cells. A fluid inlet for introducing into the chamber; a gas outlet for opening the battery housing case to discharge a combustible gas generated from the unit cell when an abnormality occurs in the unit cell; It is characterized by providing.

In the battery module according to the present invention, when a unit cell abnormality occurs, an inert fluid is introduced into the chamber from the fluid inlet, and the combustible gas generated from the unit cell is discharged from the gas outlet.

According to the present invention, since the combustible gas from the unit cell is quickly discharged from the gas discharge port, it is possible to reduce the risk of burning or ignition due to retention of high-temperature combustible gas. Further, since the combustible gas is quickly discharged from the gas discharge port, the inert fluid can be made to act on the unit cell accurately, and as a result, the risk of burning or firing the battery can be reduced.

3 is a cross-sectional view schematically showing the configuration of a unit cell used in the battery module in Embodiment 1. FIG. It is a figure explaining the outline of the battery module which concerns on Embodiment 1. FIG. In the battery module which concerns on Embodiment 2, it is a figure explaining the state which injects an inert fluid in a battery storage case using a fire extinguisher. It is a figure explaining the outline of the battery module which concerns on Embodiment 3 which has an exclusive exhaust chamber for discharging | emitting a combustible gas. It is the fragmentary sectional view which expanded the vicinity of the one end part of the unit cell by which the partition wall was arrange | positioned.

Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. However, the embodiments are for facilitating understanding of the principle of the present invention, and the scope of the present invention is as follows. The present invention is not limited to the embodiments, and other embodiments in which those skilled in the art appropriately replace the configurations of the following embodiments are also included in the scope of the present invention.

(Embodiment 1)
FIG. 1 is a cross-sectional view schematically showing a configuration of a unit cell used in the battery module in the present embodiment. As the unit cell 100 used in the battery module of the present invention, for example, a cylindrical lithium ion secondary battery as shown in FIG. 1 can be adopted. This lithium ion secondary battery is provided with a safety valve mechanism that releases gas to the outside of the battery when the pressure in the battery increases due to the occurrence of an abnormality such as an internal short circuit. Hereinafter, a specific configuration of the unit cell 100 will be described with reference to FIG.

As shown in FIG. 1, in the unit cell 100, an electrode group 104 in which a positive electrode 101 and a negative electrode 102 are wound through a separator 103 is housed in a battery case 107 together with a non-aqueous electrolyte.

Insulating plates

109 and 110 are arranged above and below the electrode group 104, the positive electrode 101 is joined to the filter 112 via the positive electrode lead 105, and the negative electrode 102 is also connected to the negative electrode terminal via the negative electrode lead 106. Is joined to the bottom.

A paste containing a positive electrode active material and a negative electrode active material is applied to the surfaces of the positive electrode and the negative electrode, respectively. As the positive electrode active material, for example _{_{_{LiMn 2 O 4, LiCoO 2,}}} LiNiO 3 , etc., can be used without particular limitation one or more of the positive electrode active material used in lithium ion batteries. As the negative electrode active material, for example, one or more negative electrode active materials used in lithium ion batteries, such as amorphous carbon and graphite carbon, can be used without particular limitation. As the non-aqueous electrolyte, for example, ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate and the like can be used.

The filter 112 is connected to the inner cap 113, and the protrusion of the inner cap 113 is joined to the metal valve plate 114. Further, the valve plate 114 is connected to a terminal plate 108 that also serves as a positive electrode terminal. The terminal plate 108, the valve plate 114, the inner cap 113, and the filter 112 are integrated to seal the opening of the battery case 107 via the gasket 111.

When an abnormality such as an internal short circuit occurs in the unit cell 100 and the pressure in the unit cell 100 increases, the valve body 114 swells toward the terminal plate 108 and the inner cap 113 and the valve body 114 are disconnected. The current path is interrupted. When the pressure in the unit cell 100 further increases, the valve body 114 is broken. As a result, the gas generated in the unit cell 100 is discharged to the outside through the through hole 112a of the filter 112, the through hole 113a of the inner cap 113, the tear of the valve body 114, and the opening 108a of the terminal plate 108. Is done.

In addition, the safety valve mechanism that discharges the gas generated in the unit cell 100 to the outside is not limited to the structure shown in FIG. For example, when the valve body is pressed against the valve seat by an elastic body and the internal pressure of the unit cell 100 becomes higher than the set pressure, a configuration in which the valve body is opened away from the valve seat can be employed.

FIG. 2 is a diagram for explaining the outline of the battery module 800 according to the present embodiment. As shown in FIG. 2, the battery module 800 includes a casing-shaped battery housing case 200 made of, for example, polycarbonate resin, and a plurality of unit cells 100 housed in the battery housing case 200. The unit cells 100 are arranged in parallel in one direction indicated by an arrow 171 and are electrically connected to each other, for example, in parallel. Each unit cell 100 is fixed at a restricted position by a rib 211 formed on the bottom 210 of the battery housing case 200. Each unit cell 100 can be held together by a battery holding frame.

A fluid introduction port 120 for allowing an inert fluid to be introduced into the battery housing case 200 when a battery abnormality occurs is opened above one wall surface of the battery housing case 200. The fluid introduction port 120 is provided with an introduction valve 121. Normally, the introduction valve 121 is closed, and the inside of the battery housing case 200 is kept sealed. When the inert fluid is ejected from the inert fluid supply means 140 described later, the introduction valve 121 is opened and the inert fluid is supplied into the battery housing case 200. The introduction valve 121 is a destruction valve that is destroyed by, for example, the dynamic pressure of the inert fluid ejected from the inert fluid supply unit 140.

On the upper side of the other wall surface of the battery housing case 200, a gas discharge port 130 is provided for discharging the combustible gas generated from the battery from the battery housing case 200 when a battery abnormality occurs. In the battery housing case 200, the gas discharge port 130 and the fluid introduction port 120 are disposed, for example, at positions facing each other in the horizontal direction. The gas discharge port 130 is provided with a discharge valve 131 similar to the introduction valve 121. Normally, the discharge valve 131 is closed, and the inside of the battery housing case 200 is kept sealed.

The inert fluid supply unit 140 is provided in the middle of the tank 141 in which the inert fluid is stored, the guide path 142 that guides the inert fluid stored in the tank 141 to the fluid inlet 120, and the guide path 142. An on-off valve 143 that opens and closes the guide path 142 and an actuator 144 that opens and closes the on-off valve 143 are provided.

The inert fluid is an inert gas, liquid, or gel. The inert fluid is not particularly limited. For example, non-reactive gas such as nitrogen, helium, argon, neon, krypton, xenon, carbon dioxide, or combustion reaction such as perfluoroketone is terminated or A fire extinguisher that prevents fire. It is also possible to contain a solid component such as powder or fine particles in the inert fluid. For example, it is possible to contain sodium hydrogen carbonate powder in carbon dioxide. When sodium bicarbonate is heated to a high temperature, it absorbs heat, generating carbon dioxide and water vapor, lowering the temperature in the battery housing case 200, keeping it in an inert atmosphere, preventing the occurrence of fire, and terminating the combustion reaction. Let

A pressure sensor 150 that detects the internal pressure of the battery housing case 200 is provided on the ceiling of the battery housing case 200. An inert fluid supply control means 151 is connected to the pressure sensor 150. Based on the detection result of the pressure sensor 150, the inert fluid supply control unit 151 discharges the combustible gas from the gas discharge port 130 when the internal pressure in the battery housing case 200 is higher than a predetermined set pressure. The on-off valve 143 is opened by operating the actuator 144, and an inert fluid is injected from the tank 141 into the battery housing case 200.

Next, the operation of the battery module 800 having the above configuration will be described. For example, it is assumed that the battery module 800 is mounted on a hybrid vehicle, and an abnormality occurs in the battery module 800 due to, for example, a flammable electrolyte ignited due to a collision of the vehicle. Combustible gas is generated from the battery due to the abnormality of the battery module 800. This combustible gas accumulates in the chamber containing the unit cell, and the pressure in the chamber rises. The pressure in the battery housing case 200 is detected by the pressure sensor 150. When the pressure becomes higher than a predetermined set pressure, the inert fluid supply control means 151 operates the actuator 144 to open the on-off valve 143. Make it. When the on-off valve 143 is opened, an inert fluid flows from the tank 141, the introduction valve 121 is destroyed by the dynamic pressure of the inert fluid, the fluid inlet 120 is opened, and the inert fluid is introduced into the battery housing case 200. . Since the pressure in the battery housing case 200 is detected by the pressure sensor 150, the inert fluid can be made to act automatically and quickly even in an emergency.

And, by the pressure of the inert fluid introduced from one wall surface of the battery housing case 200 in this way, the combustible gas generated from the battery is pushed to the other wall surface of the battery housing case 200 as shown by the arrow 172, The exhaust valve 131 of the gas exhaust port 130 is destroyed by the dynamic pressure of the flow, and the combustible gas is exhausted from the gas exhaust port 130. At the same time, the inert fluid introduced from the gas inlet 120 acts on the unit cell 100 as indicated by an arrow 173. In this manner, the combustible gas is discharged from the gas discharge port 130, and the inert gas is filled in the battery housing case 200 to act on the unit cell 100, so that the combustion or ignition of the battery in the event of an abnormality occurs. Risk can be reduced.

In the above-described embodiment, the pressure sensor 150 is provided in the battery housing case 200. However, the scope of the present invention is not limited to such an embodiment. For example, instead of the pressure sensor 150, a battery housing is provided. A temperature sensor for detecting the temperature of the case 200 is provided, and the inert fluid supply control means 151 is based on the detection result of the temperature sensor, and when the temperature in the battery housing case 200 is higher than a predetermined set temperature, the inert fluid Can be injected into the battery housing case 200 to discharge the combustible gas from the gas discharge port 130.

Further, for example, instead of the pressure sensor 150, a gas sensor for detecting the combustible gas in the battery housing case 200 is provided, and the inert fluid supply control means 151 is provided in the battery housing case 200 based on the detection result of the gas sensor. When a predetermined amount or more of combustible gas is detected, it is possible to inject an inert fluid into the battery housing case 200 and discharge the combustible gas from the gas discharge port 130. Further, the pressure sensor 150, the temperature sensor, and the gas sensor may be provided alone or in combination.

(Embodiment 2)
In the first embodiment described above, the pressure sensor 150 that detects the internal pressure of the battery housing case 200 is provided, and when the internal pressure in the battery housing case 200 is higher than a predetermined set pressure, the inert fluid supply control means. 151, the inert fluid is automatically injected into the battery housing case 200. In the second embodiment, as shown in FIG. 3, the inert fluid is manually housed in the battery using a fire extinguisher. The case where it injects in case 200 is demonstrated.

FIG. 3 is a diagram for explaining an outline of the battery module 800 that uses the fire extinguisher 500 to inject an inert fluid into the battery housing case 200. As shown in FIG. 3, one end (downstream side) of the extinguishing agent introduction path 122 for introducing the extinguishing agent is connected to the fluid introduction port 120. Further, the other end (upstream side) of the extinguishant introduction path 122 is connected to a nozzle insertion port 123 for inserting the extinguishing agent nozzle 510 of the extinguisher 500.

The gas discharge port 130 is connected to one end of a discharge path 132 for discharging the combustible gas, and the other end is provided with an exhaust port 133. In this way, the gas discharge port 130 is provided. Is disposed at an extended position as the exhaust port 133. For example, when the battery module 800 is mounted on an automobile or the like, the exhaust port 133 and the nozzle insertion port 123 are installed at positions close to each other due to design restrictions and the like. The nozzle insertion port 123 is provided with identification means for identifying the user of the fire extinguisher 500 between the nozzle insertion port 123 and the exhaust port 133. Although this identification means is not particularly limited, a means having distinctiveness can be used from color, shape, or a combination thereof. For example, a fluorescent color sticker or an arrow shape indicating the location of the nozzle insertion port 123 is used. Or the like can be used.

Next, the operation of the battery module 800 having the above configuration will be described. For example, it is assumed that an abnormality occurs in the battery module 800 due to, for example, a flammable electrolyte ignited due to a collision of an automobile on which the battery module 800 is mounted. Combustible gas is generated from the battery due to the abnormality of the battery module 800. A user of an automobile uses, for example, a fire extinguisher 500 installed in the car in advance, and inserts the fire extinguishing agent nozzle 510 of the fire extinguisher 500 into the nozzle insertion port 123. At this time, since the identification means is provided in the nozzle insertion port 123, the user of the fire extinguisher 500 can accurately enter the nozzle insertion port 123 without making a mistake with the exhaust port 133 even in an emergency in which an abnormality occurs in the battery module 800. The fire extinguisher nozzle 510 of the fire extinguisher 500 can be inserted. Thereafter, the fire extinguisher 500 is operated, and the inert fluid is introduced into the battery housing case 200. The combustible gas is pushed toward the gas outlet 130 as indicated by the arrow 172, and the inert fluid acts on the unit cell 100 as indicated by the arrow 173. In this manner, the combustible gas is discharged from the gas discharge port 130, and the inert gas is filled in the battery housing case 200 to act on the unit cell 100, so that the combustion or ignition of the battery in the event of an abnormality occurs. Risk can be reduced.

In the above-described embodiment, the identification unit provided in the nozzle insertion port 123 is a unit having identification from color, shape, or a combination thereof, but is not limited to such an embodiment. For example, the base structure of the nozzle insertion port 123 can be fitted to the fire extinguisher nozzle 510, but the base structure of the exhaust port 133 cannot be fitted to the fire extinguisher nozzle 510. It is also possible to distinguish between the nozzle insertion port 123 and the exhaust port 133.

(Embodiment 3)
In the first and second embodiments, the combustible gas is discharged into the battery housing case 200. However, in the third embodiment, a dedicated gas for discharging the combustible gas into the battery housing case 200 is used. An exhaust chamber is provided.

FIG. 4 is a diagram illustrating an outline of a battery module 800 having a dedicated exhaust chamber 202 for discharging combustible gas. As shown in FIG. 4, in the third embodiment, the battery housing case 200 is formed on the partition wall 203 disposed on one end side of the plurality of unit cells 100 (in the present embodiment, the terminal plate 108 side also serving as the positive electrode terminal). Thus, the battery chamber 201 is divided into a battery chamber 201 and an exhaust chamber 202 that discharges combustible gas discharged from the open portion 108a of the unit cell 100 accommodated in the battery chamber 201. The open part 108 a of the unit cell 100 communicates with the exhaust chamber 202 through an opening 203 a formed in the partition wall 203. A fluid introduction port 120 is provided on one wall surface of the exhaust chamber 202, and a gas discharge port 130 is provided on the other wall surface.

The plurality of unit cells 100 arranged in the battery chamber 201 includes the above-described safety valve mechanism so as to discharge the combustible gas to the exhaust chamber 202. That is, FIG. 5 is an enlarged partial cross-sectional view of the vicinity of one end of the unit cell 100 in which the partition wall 203 is disposed. As shown in FIG. 5, a sheet-like elastic member 231 such as silicone is bonded to the lower surface of the partition wall 203, and the protruding portion of the terminal plate 108 is inserted into the opening 203 a of the partition wall 203. Thus, the elastic member 231 seals between the upper portion of the shoulder 107 a of the battery case 107 and the partition wall 203.

The partition wall 203 is a non-breathable partition wall. Therefore, the combustible gas discharged from the open portion 108 a provided on the protruding portion of the terminal plate 108 does not return to the battery chamber 201 again through the partition wall 203. The partition wall 203 does not move the combustible gas discharged into the exhaust chamber 202 to the battery chamber 201, but the inert fluid introduced into the exhaust chamber 202 is movable to the battery chamber 201 via the partition wall 203. The body is desirable. Such a partition wall 203 is configured by, for example, laminating a porous gas separation membrane that does not transmit a combustible gas but transmits an inert fluid.

Next, the operation of the battery module 800 having the above configuration will be described. A combustible gas is generated in the exhaust chamber 202 when an abnormality occurs in the battery module 800 due to ignition of the flammable electrolyte and the safety valve mechanism of the unit cell 100 is opened. When this combustible gas accumulates in the exhaust chamber 202 and its pressure rises, and the pressure detected by the pressure sensor 150 becomes higher than a predetermined set pressure, the inert fluid supply control means 151 operates the actuator 144. The on-off valve 143 is opened. When the on-off valve 143 is opened, an inert fluid flows from the tank 141 into the exhaust chamber 202, and the combustible gas is pushed out and discharged from the gas discharge port 130 as indicated by an arrow 172. Since the exclusive exhaust chamber 202 for exhausting the combustible gas is provided, the combustible gas can be quickly exhausted from the gas exhaust port 130, thereby causing the risk of combustion or ignition due to retention of the high temperature combustible gas. Can be reduced.

Here, when the partition wall 203 is the wall body described above, the combustible gas discharged into the exhaust chamber 202 does not move to the battery chamber 201, but the inert fluid introduced into the exhaust chamber 202 is indicated by an arrow 173. Thus, it can move to the battery chamber 201 through the partition wall 203. Therefore, the inert fluid can act on the unit cell 100 in which an abnormality has occurred, and as a result, the risk of firing or firing of the battery can be further reduced.

(Other embodiments)
In the above-described embodiment, the present invention is the battery module 800. However, a battery pack in which a plurality of the battery modules 800 are combined by at least one of serial connection and parallel connection may be used. In such a case, only one tank 141 in which an inert fluid is stored is installed in a plurality of battery modules 800, and the tank 141 is connected to each fluid inlet 120 of each battery module 800. Thus, it is preferable that the guide path 142 has a branched structure. The occurrence of battery abnormality is a very rare exceptional phenomenon. For this reason, providing a tank 141 for storing an inert fluid for each battery module increases the number of parts and is uneconomical.

Further, in the above-described embodiment, the unit cell 100 is a lithium ion secondary battery, but the scope of the present invention is not limited to this, and for example, any battery that can be charged, such as a nickel metal hydride battery or a nickel cadmium battery. A battery can be used.

The present invention can be used as a battery module that requires high capacity and high voltage, such as a hybrid vehicle or an electric vehicle, and that requires high reliability and safety.

DESCRIPTION OF SYMBOLS 100: Unit cell 101: Positive electrode 102: Negative electrode 103: Separator 104: Electrode group 105: Positive electrode lead 106: Negative electrode lead 107: Battery case 108: Terminal board 109,110: Insulation board 111: Gasket 112: Filter 113: Inner cap 114 : Valve body 120: Fluid inlet 121: Inlet valve 122: Fire extinguisher inlet path 123: Nozzle insertion port 130: Gas outlet 131: Drain valve 140: Inert fluid supply means 141: Tank 142: Guide path 143: On-off valve 144: Actuator 150: Pressure sensor 151: Inert fluid supply control means 200: Battery housing case 201: Battery chamber 202: Exhaust chamber 203: Partition wall 203a: Opening 2311: Elastic member 500: Fire extinguisher 510: Fire extinguisher nozzle 800 : Battery module

Claims

A plurality of unit cells;
A battery housing case having a chamber for housing the plurality of unit cells;
A fluid introduction port that is opened in the battery housing case and allows an inert fluid to be introduced into the chamber when a unit cell abnormality occurs;
A battery module, comprising: a gas discharge port that is opened in the battery housing case and discharges combustible gas generated from the unit cell from the chamber when a unit cell abnormality occurs.
A pressure sensor for detecting the internal pressure of the chamber;
Based on the detection result of the pressure sensor, when the internal pressure of the chamber is higher than a predetermined set pressure, an inert fluid is discharged from the fluid inlet to the chamber so that the combustible gas is discharged from the gas outlet. The battery module according to claim 1, further comprising an inert fluid supply control unit that is introduced into the battery module.
A temperature sensor for detecting the temperature of the chamber;
Based on the detection result of the temperature sensor, when the temperature of the chamber is higher than a predetermined set temperature, the inert fluid is discharged from the fluid inlet to the chamber so that the combustible gas is discharged from the gas outlet. The battery module according to claim 1, further comprising an inert fluid supply control unit that is introduced into the battery module.
A gas sensor for detecting the presence of the combustible gas in the chamber;
Based on the detection result of the gas sensor, an inert fluid is supplied to the fluid inlet so that the combustible gas is discharged from the gas outlet when a predetermined amount or more of the combustible gas is detected in the chamber. 4. The battery module according to claim 1, further comprising an inert fluid supply control unit that is introduced into the chamber.
The unit cell is provided with a safety valve mechanism that releases the combustible gas generated when an abnormality occurs to the outside of the unit cell,
The chamber is partitioned by a partition wall into a battery chamber in which the plurality of unit cells are accommodated and an exhaust chamber for discharging a combustible gas discharged from the safety valve mechanism of the unit cells accommodated in the battery chamber. Has been
The fluid inlet is provided on a predetermined wall surface of the exhaust chamber,
5. The battery module according to claim 1, wherein the gas discharge port is provided on another wall surface different from the predetermined wall surface. 6.
The battery module according to any one of claims 1 to 5, wherein the inert fluid is a fire extinguishing agent.
One end is connected to the fluid introduction port, and includes a fire extinguishing agent introduction path for introducing the fire extinguishing agent into the fluid introduction port,
The battery module according to claim 6, further comprising a nozzle insertion port for inserting a fire extinguishing agent nozzle of the fire extinguisher that discharges the fire extinguishing agent at the other end of the fire extinguishing agent introduction path.
The battery module according to claim 7, further comprising an identification unit that allows a user of the fire extinguisher to identify the nozzle insertion port and the gas discharge port.
A battery pack comprising a plurality of battery modules according to any one of claims 1 to 8 combined by at least one of serial connection and parallel connection.