JP5378670B2 - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack capable of securing safety without turning into an inflammable state, even if batteries housed in it discharge high-temperature gas in an emergency. <P>SOLUTION: The battery pack has an exhaust duct 1C to circulate gas discharged from the batteries, with which 1C, gas temperature is lowered to discharge the gas outside. A flow channel area of the exhaust duct 1C is in a range between 0.5 mm<SP>2</SP>or more per 1Ah of a battery capacity and 15 mm<SP>2</SP>or less. The exhaust duct 1C has provided a gas cooling part 1L and a spark trap part 1M. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a battery pack that can ensure safety without emitting flames or smoke to the outside even if an abnormality occurs in the battery.

  In recent years, with the diversification of electronic devices, batteries and battery packs with high capacity, high voltage, high output and high safety have been demanded. As a means for providing a particularly safe battery or battery pack, the battery generally has a PTC or a thermal fuse for preventing the battery temperature from rising, and further protects the battery by detecting the internal pressure of the battery to cut off the current. Means and the like are provided. The battery pack is equipped with a safety circuit and is controlled so that the battery does not become abnormal.

  However, even if a conventional protective means is provided, an abnormality may occur inside the battery, and high-temperature and high-pressure gas may be ejected from the battery. In that case, the battery pack housing is damaged, melted, or burned, and high-temperature and high-pressure gas leaked outside the battery pack, or high-temperature and high-pressure gas burned and spread inside and outside the battery pack. Is considered to be large.

As a method to prevent such a phenomenon, in a battery module in which a plurality of batteries are housed in a case, the temperature and pressure are lowered while diffusing the high-temperature and high-pressure gas released from the battery in the case, and released to the outside of the case. A plurality of cells having a safety valve that releases gas when the internal pressure of the battery is increased to a predetermined value or more to form a single cell group, and the single cell is discharged An inflatable bag is provided in the duct that discharges gas to the outside, and when a large amount of gas is generated, the bag expands to reduce the pressure of the exhaust gas and discharge the gas to the outside without causing damage to the duct A method (Patent Document 2) has been proposed.
JP 2005-322434 A JP 2005-339932 A

  However, since the gas discharged from the battery is high temperature and high pressure and highly flammable, it may ignite when it is brought into contact with and mixed with oxygen in the atmosphere. Therefore, when the means for relaxing the temperature and pressure of the exhaust gas described in Patent Documents 1 and 2 is used in the space, the gas is mixed with oxygen in a case containing a plurality of batteries or in an exhaust duct. The gas ignited by the above becomes a high temperature and high pressure state. For this reason, even the other batteries started thermal runaway, and there was a problem that the entire battery pack was damaged and the damage was increased.

  The present invention was developed with the object of solving such drawbacks, and the object of the present invention is that a battery housed in a battery pack is in a combustion state even when a high temperature gas is released in an abnormal state. The object is to provide a battery pack that can ensure safety.

In order to achieve the above object, the present invention provides a battery pack having a configuration in which a battery is housed in a housing, and has a path through which a gas discharged from the battery is circulated, and the temperature of the gas in the path. The duct is configured so that the gas flow is combined into one, the gas flow is combined into one, the flow is regulated so that it does not disperse, and the gas tightness is secured so that the gas does not leak out. There is provided as the path, the cross-sectional area of the pathway is the battery capacity 1Ah per 0.5 mm ² or more with a gas discharge portion communicating with the path, and 15 mm ² Ri following ranges der, the path , that contains the bent portion for bending a flowing direction of gas.

  In the present invention, the gas temperature is lowered to a temperature at which combustion does not occur before the gas is discharged to the outside, so that the gas discharged to the outside can be prevented from burning.

  A duct is provided as the path. Thereby, the distribution route of gas can be regulated by the duct. For this reason, it can suppress that gas is mixed with oxygen, and it can control effectively that it shifts to a combustion state before gas temperature falls.

The cross-sectional area of the path is in the range of 0.5 mm ² or more and 15 mm ² or less per 1 Ah capacity of the battery having the gas discharge portion communicating with the path. Thereby, it is suppressed that gas contacts oxygen in the air in the path, and combustion in the path is suppressed.

Further, the path includes a bent portion that bends the gas flow direction. Therefore, when a spark is generated from the gas, the gas flowing direction and the spark ejecting direction can be separated at the bent portion. As a result, the gas can be prevented from flowing with a spark, and the gas can be prevented from burning.

  It is preferable that the path is configured to circulate the gas so that the gas flow rate does not decrease below a predetermined value.

  In this way, the gas flows without lowering the gas flow rate below a predetermined value, so that it is possible to suppress the gas from coming into contact with oxygen in the main pipe. For this reason, even if gas is high temperature, it can suppress reaching combustion.

  Moreover, it is preferable that a heat exchange means or a heat absorption means for lowering the temperature of the gas is provided in the path. In this aspect, the gas temperature can be efficiently reduced to a temperature at which the gas does not burn.

  Further, it is preferable that a means for trapping a spark generated in the gas is provided in the path. In this aspect, the combustion of gas can be reliably suppressed by removing the spark that causes ignition.

  Moreover, it is preferable that the gas discharge | release part of each battery is connected to the said path | route so that the gas from a some battery can flow in. In this aspect, even when gas is released from one battery, it is possible to avoid a situation where another battery is exposed to high temperature and spreads by suppressing the gas from burning. .

  In the battery pack, the battery and the path are preferably configured to be detachable from each other.

  As described above, according to the present invention, combustion of high-temperature gas discharged from the battery can be suppressed, and a battery pack with higher safety can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  The battery pack according to the present embodiment is a battery pack in which a plurality of batteries are arranged in a housing. The battery may release a high-temperature gas at a high speed in the event of an abnormality, but the battery pack has a path for discharging the gas released from the battery to the outside. It is configured to be discharged.

  In this battery pack, even if a battery in the battery pack generates heat due to an internal short circuit or overcharge, and a hot gas is ejected from the inside of the battery, the temperature of the gas is lowered and then released to the outside of the battery pack. For this reason, it is possible to suppress gas combustion and minimize damage. In general, when gas is released outside the battery at a high temperature, the gas is mixed with oxygen outside the battery and reaches combustion. However, as in the battery pack of the present embodiment, if the gas temperature is lowered before being mixed with air, the gas will not burn even if the gas is subsequently mixed with air. That is, “reducing the gas temperature” referred to herein means reducing the gas temperature to a temperature at which the gas does not burn even when mixed with air.

  In addition, as means for suppressing mixing with air until the temperature of the gas decreases, a gas path is formed by providing a duct inside the casing, or a partition plate is arranged inside the casing. It is effective to form the path. The purpose of this is to consolidate the exhaust gas flow and regulate the flow so that it does not disperse. If the gas flow direction is not regulated, the gas will disperse in the non-directional direction within the housing, causing moderate mixing with the oxygen in the housing, before the gas temperature drops. It enters the combustion state. And it is important to ensure the sealing property of the duct so that the released gas does not leak from the duct. It is also effective to arrange the batteries so that the gaps between the batteries and the diameter of the duct do not become too narrow.

  As a material for the partition plate and duct inside the housing, a nonflammable solid such as a metal such as aluminum, copper, and titanium, ceramic, and sand can be used. In addition, when nonflammable solids are not used, all of the path through which the gas passes, such as hydrated compounds, imidazolium salt-based, pyridinium salt-based, aliphatic quaternary ammonium salt-based ionic liquids, etc. It is possible to prevent the exhaust path from being damaged by heat by partially covering and laminating.

  Moreover, it can be made more effective by providing a heat exchange means or a heat absorption means for lowering the temperature of the gas in the path through which the gas passes. The heat exchanging means or the heat absorbing means can be constituted by a high heat conductive material such as metal or a high specific heat material such as ceramic, and is also melted and sublimated by heat of solder, solder, low melting point glass, water or the like. It is also possible to use a material that absorbs heat as latent heat, or a material that absorbs heat by decomposition, such as magnesium carbonate or aluminum hydroxide. Moreover, you may disperse | distribute the heat of gas to the other cell which is not igniting in the middle of a path | route. Moreover, you may comprise a heat exchange means or a heat absorption means by providing a fin in a duct.

  Even if the gas is lowered to a temperature at which it does not ignite spontaneously, if the gas contains sparks, the gas may ignite and burn. Therefore, before the gas mixes with air, it is necessary to remove the sparks contained in the gas. As a means for trapping the spark contained in the gas in the path through which the gas passes, the trapping of the spark can be realized by forming a long conduit structure in the path through which the gas passes. Further, as a configuration of the gas path, the duct may be configured to have a bent portion such as a 99-fold or a spiral, or the bent portion may be realized by providing a plurality of protrusions in the gas path. It is also effective to provide a pocket in which a spark enters the bent portion. However, it is necessary to consider the inner diameter of the duct and the angle and number of the bent portions so as not to hinder gas discharge. The material of the duct is preferably a metal such as copper, aluminum or stainless steel in consideration of heat dissipation and heat resistance. In addition to the duct structure, a bent portion may be simply provided in the path, or exhaust gas may be blown onto the ceramic / metal plate.

The flow path area of the gas path is determined by the capacity per battery cell arranged in the battery pack. That is, since the amount of gas released from the battery is determined according to the capacity per battery cell, if the flow area of the gas path is determined by the ratio with respect to the battery capacity, the gas flow rate will not decrease below a predetermined value. Can be distributed. The predetermined value of the gas flow rate means a gas flow rate that suppresses oxygen from entering the gas path and suppresses contact between the gas and oxygen. From this point of view, the gas flow path area is preferably in the range of 0.5 mm ² or more and 15 mm ² or less per 1 Ah of battery capacity. When the gas path is formed by a duct, the flow path area is the duct flow path area.

  The gas cooling mechanism and the spark trapping mechanism may be provided in the opening of the battery pack or in each battery in the battery pack as long as the gas passes therethrough, or provided on the device on which the battery is mounted. Also good. In this case, it is necessary to configure the gas path so that the gas can be released to the outside of the device.

  Next, an embodiment of the battery pack according to the present invention will be described. As shown in FIG. 1, the battery pack according to this embodiment uses six batteries in which two cylindrical 18650 size lithium ion secondary batteries are arranged in parallel and three sets are connected in series. The assembled battery 1D is accommodated. The battery-equipped device according to the embodiment of the present invention is equipped with the battery pack shown in FIG. 1 and uses it as a power source, such as an electronic device such as a portable personal computer or a video camera, a four-wheeled vehicle, a two-wheeled vehicle, etc. Vehicles and other battery-equipped devices. When the battery-mounted device is a vehicle, the battery pack is used, for example, as a power source for an electrical device mounted on the vehicle, or as a power source for a power source such as an electric vehicle or a hybrid car.

  The battery pack includes battery pack housings 1A and 1B, a battery pack terminal (not shown) for taking out electricity, and an exhaust duct 1C. The casings 1A and 1B are made of polycarbonate, and the exhaust duct 1C is made of iron having a thickness of 0.3 mm. The exhaust duct 1C is made of metal such as nickel, aluminum, titanium, copper, and stainless steel, heat resistant resin such as liquid crystalline wholly aromatic polyester, polyethersulfone, and aromatic polyamide, or a laminate of metal and resin. You may be comprised with materials, such as a body.

  In the two batteries constituting one set, the connection plate 1E is welded to the battery terminal 1F and the battery bottom. Therefore, these two batteries are connected in parallel. The connection plate 1E is electrically connected to another set of connection plates 1E via the connection leads 1G, and is electrically connected to the battery pack terminal via the connection leads 1G. In FIG. 1, the connection plate 1E is shown only for the top set, but the connection plates 1E are similarly provided for the other sets of batteries.

  The exhaust duct 1C includes a connecting pipe portion 1H, a main pipe portion 1I, a gas cooling portion 1L, a spark trap portion 1M, and an exhaust port 1P. The main pipe portion 1I is formed in a straight tube having a substantially constant cross-sectional area, and is arranged so as to be parallel to the longitudinal direction of the battery.

  In the present embodiment, since two batteries are included in each set, two main pipe portions 1I are provided accordingly. That is, two batteries are arranged in the width direction of the casings 1A and 1B, and three batteries are arranged in the longitudinal direction in that state. Accordingly, each main pipe portion 1I is connected to three batteries adjacent in the longitudinal direction of the casings 1A and 1B. And as shown in FIG. 2, each main pipe part 1I is arrange | positioned using the space formed between the two batteries arranged in parallel and housing | casing 1A, 1B. Thereby, it is suppressed that the space in housing | casing 1A, 1B becomes large. The main pipe portion 1I is not limited to a straight tube shape, and may have a bent portion according to the arrangement relationship of the assembled battery 1D.

  The connecting pipe part 1H connects the gas discharge part of the battery and the main pipe part 1I. The connecting pipe portion 1H is in close contact with the battery terminal 1F with a high heat resistant adhesive or the like so as to guide the gas discharged from the gas discharge portion of the battery without leaking.

  In addition, as shown in FIGS. 13 to 17, the battery terminal 1F and the connecting pipe portion 1H can be detachable by using a flange joint using an O-ring, a one-touch joint, a connection using a cap nut, or the like. it can. The specific configuration of FIGS. 13 to 17 will be described in detail later.

  The gas discharge part is configured by an exhaust port provided in the battery terminal 1F, and is provided to let the gas generated inside the battery escape to the outside of the battery. In addition, this gas discharge | release part is normally obstruct | occluded and will fracture | rupture and will discharge gas, if the gas more than predetermined pressure generate | occur | produces in a battery at the time of abnormality.

  The connecting pipe portion 1H is disposed so as to extend from the battery terminal 1F in the width direction of the battery, and communicates with the main pipe portion 1I at the outer end portion. Therefore, the connecting pipe part 1H also functions as a bent part bent with respect to the main pipe part 1I.

The channel area in the connecting pipe portion 1H is set to be substantially the same as the channel area in the main pipe portion 1I. These flow passage areas are set so that the flow velocity of the gas discharged from the battery and flowing in the duct 1C does not become a predetermined value or less. Specifically, the battery capacity of the cylindrical 18650 size lithium ion secondary battery used in the present embodiment is 2 Ah, the flow path area in the connecting pipe portion 1H and the main pipe portion 1I is 5 mm ² or more, and It is 20 mm ² or less.

  The gas cooling part 1L is connected to the end of the main pipe part 1I opposite to the connecting pipe part 1H. The gas cooling part 1L is connected to both main pipe parts 1I. Accordingly, the gas that has flowed through any main pipe portion 1I flows into the gas cooling portion 1L. The gas cooling unit 1L is for cooling the gas that has flowed through the duct 1C before it is led out of the duct 1C. The gas cooling unit 1L has a structure in which a heat absorbent such as a high heat transfer material or a high specific heat material is provided on the inner wall surface. The gas cooling unit 1L is formed with a height of 3.6 mm and an internal space height of 3.0 mm, for example.

  The spark trap part 1M is disposed adjacent to the gas cooling part 1L, and as shown in FIG. 3, the spark trap part 1M and the gas cooling part 1L communicate with each other through a connecting pipe 1N. The spark trap portion 1M is provided for collecting sparks in the gas, and a porous ceramic plate, gel sheet, copper mesh, aluminum mesh, SUS mesh, cement plate or gypsum plate is provided on the inner wall surface. It is a thing of composition. An exhaust port 1P is provided in the spark trap portion 1M, and the gas that has passed through the spark trap portion 1M is discharged out of the duct 1C through the exhaust port 1P. Therefore, the gas discharged from the battery is guided from the connecting pipe part 1H to the main pipe part 1I, passes through the main pipe part 1I, then passes through the gas cooling part 1L, and then passes through the spark trap part 1M and is discharged into the exhaust port. It is discharged outside the housing through 1P. The exhaust port 1P also functions as a connection part for detaching from an outer path (not shown) provided in the battery-equipped device.

  In the present embodiment, the gas flows from the gas cooling unit 1L to the spark trap unit 1M. However, the gas may flow from the spark trap unit 1M to the gas cooling unit 1L. Moreover, the gas cooling part 1L and the spark trap part 1M are not limited to the structure arrange | positioned adjacently. Moreover, these may be formed integrally, or they may be provided in the connecting pipe portion 1H or the main pipe portion 1I.

  FIG. 4 is a schematic longitudinal sectional view of the battery according to the embodiment of the present invention. In FIG. 4, the cylindrical lithium ion battery includes a cylindrical electrode plate group 2D wound in a spiral shape. The electrode plate group 2D includes a positive electrode plate 2A in which a positive electrode mixture is applied to an aluminum foil current collector, a negative electrode plate 2B in which a negative electrode mixture is applied to a copper foil current collector, and an electrode plate group 2D disposed between the two electrodes. And a separator 2C having a thickness of 25 μm.

  A positive electrode lead current collector 2E is laser welded to the aluminum foil current collector. A negative electrode lead current collector 2F is resistance-welded to the copper foil current collector. The electrode plate group 2D is housed in a metal bottomed case 2G. The negative electrode lead current collector 2F is resistance-welded and electrically connected to the bottom of the bottomed case 2G. The positive electrode lead current collector 2E is electrically connected by laser welding from the open end of the bottomed case 2G to a metal filter 2I of a sealing plate 2H having an explosion-proof valve.

  A non-aqueous electrolyte is injected from the open end of the bottomed case 2G. A groove is formed in the open end of the bottomed case 2G, a positive electrode lead current collector 2E is bent, and a resin outer gasket 2J and a sealing plate 2H are attached to the seat of the bottomed case 2G. The entire open end of the case 2G is crimped and sealed.

  Here, the structure for detachably connecting the connecting pipe portion 1H and the battery terminal 1F shown in FIGS. 13 to 17 will be described. First, in FIG.13 and FIG.14, the flange part 5A formed in the terminal of the connecting pipe part 1H is fixed with the volt | bolt B1 with respect to the sealing board 2H, The inside of the sealing board 2H, and the connecting pipe part 1H A configuration is disclosed in which the sealing plate 2H and the connecting pipe portion 1H are connected in a state where the inside communicates with the opening 5C formed in the sealing plate 2H. Between the flange portion 5A and the sealing plate 2H, an O-ring 5B is sandwiched at an inner position of the bolt B1, and gas flow between the sealing plate 2H and the connecting pipe portion 1H is performed by the O-ring 5B. Is blocked.

  In FIG. 15, the male threaded portion 6A projecting from the sealing plate 2H and the female threaded portion 6B formed at the end of the connecting tube portion 1H are screwed together to connect the connecting tube portion 1H to the battery terminal 1F. An attachable configuration is disclosed. In the screwed state of the screw portions 6A and 6B, the packing 6C is sandwiched between the end surface of the male screw portion 6A and the bottom surface of the female screw portion 6B, and the sealing plate 2H and the connecting pipe portion 1H are sandwiched by the packing 6C. Gas flow between them is blocked.

  In FIG. 16, the outer cylinder part 7B formed at the end of the connecting pipe part 1H is put on the outer side of the inner cylinder part 7A protrudingly formed on the sealing plate 2H, thereby forming the cylinder parts 7A and 7B, respectively. In addition, a configuration is disclosed in which the claw portions 7C and 7D are engaged with each other to prevent the connecting tube portion 1H from coming off from the sealing plate 2H. In this retaining state, the packing 7E is sandwiched between the end surface of the inner cylinder portion 7A and the bottom surface of the outer cylinder portion 7B, and the gas between the sealing plate 2H and the connecting pipe portion 1H is held by the packing 7E. Distribution is blocked. The engagement of the claw portions 7C and 7D can be realized through elastic deformation to the outside of the outer cylinder portion 7B. However, in this case, the elastic deformation of the outer cylinder portion 7B is achieved. It is preferable to provide a restraining cylinder 7F for restricting and maintaining the engaged state of both the claw parts 7C and 7D on the outer side of the outer cylinder part 7B.

  In FIG. 17, the both ends of the sleeve 8C are threadedly engaged with the female threaded portion 8A protruding from the sealing plate 2H and the female threaded portion 8B formed at the end of the connecting pipe 1H. The structure by which the pipe part 1H and the sealing board 2 are connected is disclosed. In this connected state, the packing 8E is sandwiched between the large-diameter portion 8D formed in the middle portion in the longitudinal direction of the sleeve 8C and the end surfaces of the female screw portions 8A and 8B, and the sealing plate is formed by the packing 8E. The flow of gas between 2H and connecting pipe portion 1H is blocked.

  Next, as shown in FIG. 1, six completed cylindrical lithium ion secondary batteries are arranged and connected in series with a nickel-made connecting plate 1E having a thickness of 0.2 mm, and battery pack terminals constituting the battery pack are arranged. An assembled battery 1D was manufactured by attaching a connection lead 1G for electrical connection to the connection plate 1E.

  Subsequently, Embodiment 1 of the battery-equipped device according to the present invention will be described. As shown in FIGS. 5 and 6, this Embodiment 1 uses six batteries in which two cylindrical 18650-sized lithium ion secondary batteries are arranged in parallel and three sets are connected in series. 1 is a notebook personal computer (hereinafter referred to as a notebook PC) 11 to which the battery pack 10 is mounted.

  Unlike the battery pack of the first embodiment, the battery pack 10 of the first embodiment includes a connecting pipe portion 10H, a main pipe portion 10I, and a connecting portion 10P as exhaust ducts. In other words, the gas cooling unit 10L, the communication passage 10Z, the spark trap unit 10M, and the exhaust port 10Y are mounted on the battery-equipped device side, that is, the main body side of the notebook PC, as external paths.

  That is, by attaching the battery pack 10 to the notebook PC 11, the exhaust duct (connecting portion 10P) on the battery pack 10 side and the external path (gas cooling portion 10L) on the notebook PC 11 side are joined at the joining location P1. Gas generated in the event of an abnormality is sent from the exhaust port 10P of the battery pack 10 to the notebook PC 11 via the joint P1, and the gas cooling unit 10L, the communication path 10Z, the spark trap unit 10M, And it discharges | releases to the side surface side on the opposite side to the user-side side surface of the notebook type PC11 through the exhaust port 10Y in order. That is, in the notebook PC 11 of the present embodiment, the gas is discharged in the direction Y2 opposite to the direction Y1 on the user side of the notebook PC 11.

  Further, the direction in which the exhaust ports 1P and 10Y are directed is not limited to the direction Y2 opposite to the direction Y1 on the user side, and may be a direction different from at least the direction Y1. For example, the directions Y3 and Y4 orthogonal to the direction on the user side can be used.

  When an abnormal situation occurs in the battery pack, the user of the device is closest to the device with the battery pack when standing in the position of human protection to minimize the impact on the human body in terms of safety Probability is high. That is, it is highly probable that human damage can be minimized by setting the exhaust port in a direction different from the user side.

  The gas that passes through the path and is exhausted from the exhaust port is further drastically reduced in temperature by being released into the atmosphere. Therefore, it is safe enough if the gas is not directly blown to the person closest to the battery pack equipment. Can be secured.

  Next, Embodiment 2 of the battery-equipped device according to the present invention will be described. In this Embodiment 2, as shown in FIGS. 7 to 9, two cylindrical lithium ion secondary batteries having a diameter of 32 mm and a height of 120 mm are arranged in parallel as one set, and three sets are connected in series. This is an electric assist type electric bicycle 14 as a battery-mounted device to which the battery pack 12 using the six batteries is attached.

  The battery pack 12 in the second embodiment includes a connecting pipe portion 12H, a gas cooling portion 12L, and a connecting portion 12P as exhaust ducts, unlike the battery packs of the respective embodiments. In other words, the spark trap portion 12M and the exhaust port 12Y are attached to the battery-equipped device side, that is, the main body side of the electric bicycle 14 as an external path.

  That is, by attaching the battery pack 12 to the electric bicycle 14, the exhaust duct (connecting portion 12P) on the battery pack 12 side and the external path (gas cooling portion 12L) on the electric bicycle 14 side are joined at the joining point P2. The gas generated at the time of abnormality is discharged to the bottom side (downward) of the electric bicycle 14 on the opposite side from the side (upper) of the passenger side of the electric bicycle 14 via the gas cooling part 12L on the battery pack 12 side and the joint P2. Is done.

  Next, Embodiment 3 of the battery-equipped device according to the present invention will be described. In Embodiment 3, as shown in FIGS. 10 to 12, six sets of cylindrical lithium ion secondary batteries having a diameter of 32 mm and a height of 120 mm are arranged as one set, and 10 sets of this are arranged in series. This is a hybrid electric vehicle 16 equipped with a battery pack 15 using 60 batteries connected in series.

  The battery pack 15 includes ten pack bodies 15A in which the six batteries are stored, and gas discharged from each battery provided in each pack body 15A and stored in each pack body. A lead-out pipe 15B that can be led out to the outside, a concentrating pipe 15C that joins the lead-out pipes 15B together, and a connecting portion 15D provided in the concentrating pipe 15C are provided.

  The electric vehicle 16 is connected to the connecting part 15D, a gas cooling part 16A, a spark trap part 16B connected to the gas cooling part 16A, a spark trap part 16B, and an engine exhaust gas. An exhaust pipe 16C for exhausting the gas guided from the battery pack 15 to the outside of the vehicle, a muffler 16D provided in the middle of the exhaust pipe 16C, and an exhaust port 16E for exhausting the gas downstream of the muffler 16D It has.

  That is, the battery pack 15 of the present embodiment includes a lead-out pipe 15B, a concentration pipe 15C, and a connection part 15D as exhaust ducts, while the electric vehicle 16 includes a gas cooling part 16A, a spark trap part 16B, an exhaust pipe 16C, and An exhaust port 16E is provided as an outer path.

  In this embodiment, by attaching the battery pack 15 to the electric vehicle 16, the exhaust duct (connecting portion 15D) of the battery pack 15 and the outer path (gas cooling portion 16A) of the electric vehicle 16 are joined at the joining portion P3. The gas generated at the time of abnormality passes through the junction P3, the gas cooling unit 16A, the spark trap unit 16B, the exhaust pipe 16C, and the exhaust port 16E from the battery pack 15 on the side opposite to the side surface (front surface) on the passenger side of the automobile. Released to the side (rear) side.

  Hereinafter, examples of the battery pack will be described.

(1) Production of positive electrode plate The positive electrode plate 2A is produced as follows. As a positive electrode mixture, 85 parts by weight of lithium cobaltate powder, 10 parts by weight of carbon powder as a conductive agent, and polyvinylidene fluoride (hereinafter abbreviated as PVDF) N-methyl-2-pyrrolidone (hereinafter referred to as PVDF) as a binder. The solution is mixed with 5 parts by weight of PVDF. This mixture is applied to an aluminum foil current collector having a thickness of 15 μm, dried, and then rolled. Thus, a positive electrode plate 2A having a thickness of 100 μm was produced.

(2) Production of negative electrode plate The negative electrode plate 2B is produced as follows. 95 parts by weight of artificial graphite powder is mixed as a negative electrode mixture, and PVDF is mixed with an NMP solution of PVDF as a binder in an amount of 5 parts by weight. This mixture is applied to a copper foil current collector having a thickness of 10 μm, dried, and then rolled. Thus, a negative electrode plate 2B having a thickness of 110 μm was produced.

(3) Preparation of non-aqueous electrolyte The non-aqueous electrolyte is prepared as follows. As a non-aqueous solvent, ethylene carbonate and ethyl methyl carbonate were mixed at a volume ratio of 1: 1, and dissolved therein so that lithium hexafluorophosphate (LiPF ₆ ) was 1 mol / L as a solute. 4.5 ml of the non-aqueous electrolyte prepared in this way is used.

(4) Production of sealed secondary battery After the separator 2C having a thickness of 25 μm is disposed between the positive electrode plate 2A and the negative electrode plate 2B and wound to form the cylindrical electrode plate group 2D, the bottomed case 2G made of metal Inserted and sealed. As a result, a sealed nonaqueous electrolyte secondary battery was obtained. This battery was a cylindrical battery having a diameter of 18 mm and a height of 65 mm, and the design capacity of the battery was 2000 mAh. The completed battery was covered with a heat-shrinkable tube made of polyethylene terephthalate having a thickness of 80 μm as a battery can insulator, and heat-shrinked with hot air at 90 ° C. to complete the battery.

(5) Production of battery pack (Example 1A)
The assembled battery 1D and the exhaust duct 1C shown in FIG. 1 were accommodated in the battery packs 1A and 1B, and the outer peripheral portions of the battery packs 1A and 1B were welded. At this time, by charging the completed battery pack with a maximum current of 3A and a charge end current of 0.1A, and normally charging 12.6V, bypassing the overcharge protection circuit of the pack and the cell current interruption (CID) The battery pack of Example 1A was obtained by charging at a constant current and a constant voltage up to 13.5 V.

(Example 1B)
A 1 mm thick porous ceramic plate (industrial ceramic honeycomb; manufactured by NGK Corporation) was attached to the inside of the spark trap portion 1M. The location of the porous ceramic plate was the facing wall of the wall to which the connecting pipe 1N was connected. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 1B.

(Example 1C)
A gel sheet having a thickness of 1 mm (manufactured by Sekisui Plastics Co., Ltd.) was attached to the inside of the spark trap portion 1M. The arrangement position of the gel sheet was the facing wall of the wall portion to which the connecting pipe 1N was connected. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 1C.

(Example 1D)
A copper mesh (wire diameter: 40 μm, opening: 45 × 45 μm) was laminated and pasted inside the spark trap portion 1M so as to have a thickness of 1 mm. The arrangement position of the copper mesh was the facing wall of the wall portion to which the connecting pipe 1N was connected. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 1D.

(Example 1E)
An aluminum mesh (wire diameter: 40 μm, mesh opening: 45 × 45 μm) was laminated and pasted inside the spark trap portion 1M to a thickness of 1 mm. The arrangement position of the aluminum mesh was the facing wall of the wall portion to which the connecting pipe 1N was connected. A battery pack was made similar to Example 1D except for the above, and the battery pack of Example 1E was obtained.

(Example 1F)
A SUS316 mesh (wire diameter: 40 μm, mesh opening: 45 × 45 μm) was laminated and pasted inside the spark trap portion 1M so as to have a thickness of 1 mm. The arrangement position of the SUS mesh was the facing wall of the wall portion to which the connecting pipe 1N is connected. A battery pack was made in the same manner as Example 1D except for the above, and the battery pack of Example 1F was obtained.

Example 1M
A cement plate having a thickness of 1 mm was prepared and attached to the inside of the spark trap portion 1M. The arrangement position of the cement plate was the facing wall of the wall portion to which the connecting pipe 1N was connected. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 1M.

Example 1N
A gypsum plate having a thickness of 1 mm was produced and attached to the inside of the spark trap portion 1M. The arrangement position of the gypsum board was the facing wall of the wall part to which the connecting pipe 1N is connected. Except for this, a battery pack was made in the same manner as in Example 1A to obtain a battery pack of Example 1N.

(Example 2A)
A 1 mm thick porous ceramic plate (industrial ceramic honeycomb; manufactured by NGK Co., Ltd.) containing moisture was attached inside the gas cooling unit 1L. The arrangement position of the porous ceramic plate was the facing wall of the wall portion to which the main pipe portion 1I is connected. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 2A.

(Example 2B)
A glass wool having a thickness of 1 mm and containing moisture was attached to the inside of the gas cooling unit 1L. The glass wool was disposed at the facing wall of the wall connected to the main pipe portion 1I. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 2B.

(Example 2C)
A hydrous gel (Heat Buster PDM Laboratories Co., Ltd.) was applied in a thickness of 1 mm inside the gas cooling unit 1L. The application position of the hydrogel was the facing wall of the wall part to which the main pipe part 1I is connected. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 2C.

(Example 2D)
A copper plate having a thickness of 1 mm was pasted inside the gas cooling unit 1L. The arrangement position of the copper plate was the facing wall of the wall portion to which the main pipe portion 1I is connected. A battery pack was made in the same manner as in Example 1A except for the above to obtain a battery pack of Example 2D.

(Example 2E)
An aluminum plate having a thickness of 1 mm was attached inside the gas cooling unit 1L. The aluminum plate was disposed at the facing wall of the wall connected to the main pipe portion 1I. A battery pack was made in the same manner as Example 1A except for this, and the battery pack of Example 2E was obtained.

(Example 2F)
A SUS316 plate having a thickness of 1 mm was pasted inside the gas cooling unit 1L. The arrangement position of the SUS plate was the facing wall of the wall portion connected to the main pipe portion 1I. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 2F.

(Example 2G)
90% by weight of ammonium dihydrogen phosphate powder (special grade (G) manufactured by Kanto Chemical Co., Ltd.) and 10% by weight of PTFE powder were kneaded in a mortar and formed into a 1 mm thick pellet. This pellet was affixed inside the gas cooling part 1L. The arrangement position of the pellet was the facing wall of the wall part to which the main pipe part 1I is connected. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 2G.

(Example 2H)
90% by weight of sodium bicarbonate (special grade (G) manufactured by Kanto Chemical Co., Ltd.) and 10% by weight of PTFE powder were kneaded in a mortar and formed into a 1 mm thick pellet. This pellet was affixed inside the gas cooling part 1L. The arrangement position of the pellet was the facing wall of the wall part to which the main pipe part 1I is connected. Except for this, a battery pack was made in the same manner as in Example 1A, and a battery pack of Example 2H was obtained.

Example 2I
90% by weight of aluminum hydroxide (special grade (G) manufactured by Kanto Chemical Co., Ltd.) and 10% by weight of PTFE powder were kneaded in a mortar and formed into a 1 mm thick pellet. This pellet was affixed inside the gas cooling part 1L. The arrangement position of the pellet was the facing wall of the wall part to which the main pipe part 1I is connected. A battery pack was made in the same manner as in Example 1A except for the above to obtain a battery pack of Example 2I.

(Example 2J)
90% by weight of magnesium carbonate (special grade (G) manufactured by Kanto Chemical Co., Ltd.) and 10% by weight of PTFE powder were kneaded in a mortar and formed into a 1 mm thick pellet. This pellet was affixed inside the gas cooling part 1L. The arrangement position of the pellet was the facing wall of the wall part to which the main pipe part 1I is connected. Except for this, a battery pack was produced in the same manner as in Example 1A to obtain a battery pack of Example 2J.

(Example 2K)
90% by weight of copper (II) sulfate pentahydrate (special grade (G) manufactured by Kanto Chemical Co., Ltd.) and 10% by weight of PTFE powder were kneaded in a mortar and formed into a 1 mm thick pellet. This pellet was affixed inside the gas cooling part 1L. The arrangement position of the pellet was the facing wall of the wall part to which the main pipe part 1I is connected. Except for this, a battery pack was made in the same manner as in Example 1A, and a battery pack of Example 2K was obtained.

(Example 2L)
90% by weight of calcium hydroxide (special grade (G) manufactured by Kanto Chemical Co., Ltd.) and 10% by weight of PTFE powder were kneaded in a mortar and formed into a 1 mm thick pellet. This pellet was affixed inside the gas cooling part 1L. The arrangement position of the pellet was the facing wall of the wall part to which the main pipe part 1I is connected. Except for this, a battery pack was made in the same manner as in Example 1A, and a battery pack of Example 2L was obtained.

(Comparative Example 1)
A battery pack was produced in the same manner as in Example 1A except that the exhaust duct 1 </ b> C was excluded, and used as Comparative Example 1.

(Comparative Example 2)
A battery pack was produced in the same manner as in Example 1 except that the exhaust duct 1C was removed, the space between the cells was reduced, and the housing size was shortened by 14.4 mm, and Comparative Example 2 was obtained.

  The following evaluations were performed on each battery pack obtained in the above examples and comparative examples.

(I) Nail penetration test A nail penetration test was performed using 10 completed battery packs and an iron nail having a diameter of 2.5 mm at an environmental temperature of 20 ° C. This nail penetration test was performed by inserting a nail at a speed of 5 mm per second until it penetrates the battery (cell) through a through hole for nail penetration previously provided in the battery pack lid. The battery pierced with a nail is one of the batteries on the opposite side of the gas cooling unit in the battery pack. The nail was pierced so as to pass through the center in the height direction and the diameter direction of the battery. The sparks and flames emitted outside the pack were observed using a high-speed camera. Outside the pack, it was determined that there was a fire when the flame was confirmed continuously for 0.5 seconds or more, and when there were 10 or more sparks confirmed within 0.1 seconds, it was determined that there was a spark. In addition, the nail penetration part was comprised so that there might be no leak of the gas from this part, a spark, and a flame through a heat resistant sealing material.

  The evaluation results are shown in Table 1.

  As shown in Table 1, in Comparative Examples 1 and 2, sparks and flames were released from various locations of the battery pack, and thereafter, it was confirmed that the battery pack was ignited and burned into cells other than the cells that had been stabbed. This is because the high-temperature gas containing sparks discharged from the nail penetration cell is not regulated in the flow path inside the battery pack, so that the gas is mixed with air at a high temperature and starts to burn. On the other hand, in Example 1A, ignition outside the pack after passing through the exhaust duct was able to suppress a considerable number of sparks at the bent portion of the exhaust duct and the wall surface of the exhaust duct. This is thought to be because the heat was taken away and the temperature became below the natural ignition temperature of the gas. That is, before the gas is ignited by mixing it with air properly, it was possible to suppress the ignition of the gas and the ignition of the pack and other batteries by reducing the gas temperature and causing the ignition. Conceivable. Moreover, since the gas flows in the exhaust duct at a gas flow rate equal to or higher than a predetermined value, the gas is prevented from coming into contact with oxygen in the air in the exhaust duct, and combustion in the exhaust duct is suppressed. . In fact, when the components of the generated gas are analyzed, in Comparative Examples 1 and 2, the oxidizing gas centered on carbon dioxide is the main component, and almost no hydrogen carbonate-based reducing gas generated by thermal decomposition or the like can be confirmed. As a result, it was found that the combustion was progressing completely. On the other hand, in Example 1A, it was confirmed that the ratio of the oxidizing gas was reduced and the ratio of the reducing gas released without burning was greatly increased.

  From Example 1B to Example 1N, the effect by providing a spark trap on the wall surface of the spark trap part 1M which a high temperature gas contacts was confirmed. Thereby, compared with Example 1A without a spark trap, it becomes possible to make the amount of sparks discharged to the outside of the pack substantially zero, and it can be confirmed that there is a significant effect for suppressing ignition of gas. It was.

  From Example 2A to Example 2L, a gas having a high heat capacity, a heat absorbing material that takes heat away by thermal decomposition or vaporization, or a material having good thermal conductivity such as metal is disposed in the high-temperature gas flow path. The temperature of the gas was reduced to suppress the ignition of the gas. The material that generates the gas needs to be a material that generates an inert gas. It was confirmed that the sparks were reduced by arranging these materials.

  In this way, by reducing the temperature of the high-temperature gas released from the inside of the battery and releasing it to the outside of the pack, a safe battery pack that does not cause gas combustion and does not cause damage to the battery pack or burning to other batteries. Can be realized.

Next, examples of battery-equipped devices will be described.
(1) Preparation of positive electrode plate A predetermined ratio of Co and Al sulfate was added to a NiSO ₄ aqueous solution to prepare a saturated aqueous solution. While stirring the saturated aqueous solution, sodium hydroxide solution was slowly added dropwise to the saturated solution. As a result, the saturated solution was neutralized, and as a result, a precipitate of ternary nickel hydroxide Ni _0.7 Co _0.2 Al _0.1 (OH) ₂ could be generated (coprecipitation method). The produced precipitate was filtered, washed with water, and dried at 80 ° C. The average particle diameter of the obtained nickel hydroxide was about 10 μm.

The obtained Ni _0.7 Co _0.2 Al _0.1 (OH) ₂ was heat treated in the atmosphere at 900 ° C. for 10 hours to obtain nickel oxide Ni _0.7 Co _0.2 Al _0.1 O. At this time, the nickel oxide Ni _0.7 Co _0.2 Al _0.1 O obtained using the powder X-ray diffraction method was diffracted to confirm that the nickel oxide Ni _0.7 Co _0.2 Al _0.1 O was a single phase nickel oxide. Then, lithium hydroxide monohydrate is added to nickel oxide Ni _0.7 Co _0.2 Al _0.1 O so that the sum of the number of Ni atoms, the number of Co atoms, and the number of Al atoms is equal to the number of Li atoms. In addition, a lithium nickel composite oxide LiNi _0.7 Co _0.2 Al _0.1 O ₂ was obtained by performing a heat treatment at 800 ° C. for 10 hours in dry air.

When the lithium nickel composite oxide LiNi _0.7 Co _0.2 Al _0.1 O ₂ obtained by the powder X-ray diffraction method is diffracted, the lithium nickel composite oxide LiNi _0.7 Co _0.2 Al _0.1 O ₂ is a single-phase hexagonal layered layer. The structure was confirmed, and it was confirmed that Co and Al were dissolved in the lithium nickel composite oxide. Then, the lithium nickel composite oxide was pulverized and classified into powder. The average particle diameter of this powder was 9.5 μm. When the specific surface area of this powder was determined according to the BET method, the specific surface area was 0.4 m ² / g.

3 kg of the obtained lithium nickel composite oxide, 90 g of acetylene black, and 1 kg of PVDF solution were kneaded together with an appropriate amount of N-methyl-2-pyrrolidone (NMP) in a planetary mixer, and a slurry-like positive electrode mixture Was made. This positive electrode mixture was applied onto an aluminum foil having a thickness of 20 μm and a width of 150 mm. At this time, an uncoated part having a width of 5 mm was formed at one end in the width direction of the aluminum foil. Thereafter, the positive electrode mixture was dried to form a positive electrode mixture layer on the aluminum foil. And after pressing so that the total thickness of the thickness of a positive mix layer and the thickness of aluminum foil may be set to 100 micrometers, the positive electrode plate A for lithium ion secondary batteries of cylindrical 18650 size, and the battery of a tabless current collection structure A positive electrode plate B was prepared. The electrode plate for a battery having a tabless current collecting structure was cut so that the width of the electrode plate was 105 mm and the width of the mixture application portion was 100 mm, thereby producing a positive electrode plate B having a tabless current collecting structure.
(2) Production of negative electrode plate Specifically, 3 kg of artificial graphite, 75 g of an aqueous solution of rubber particles (binder) made of a styrene-butadiene copolymer (solid weight: 40% by weight), carboxy 30 g of methylcellulose (CMC; carboxymethylcellulose) was kneaded with a suitable amount of water in a planetary mixer to prepare a slurry-like negative electrode mixture. This negative electrode mixture was applied onto a copper foil having a thickness of 10 μm and a width of 150 mm. At this time, an uncoated part (exposed part) having a width of 5 mm was formed at one end in the width direction of the copper foil. Thereafter, the negative electrode mixture was dried to form a negative electrode mixture layer on the copper foil. Then, after pressing so that the total thickness of the negative electrode mixture layer and the copper foil becomes 110 μm, the negative electrode plate A for a lithium ion secondary battery having a cylindrical 18650 size and a battery having a tabless current collecting structure The negative electrode plate B was prepared. The electrode plate for a battery having a tabless current collection structure was cut so that the width of the electrode plate was 110 mm and the width of the mixture application portion was 105 mm, thereby preparing a negative electrode having a tabless current collection structure.
(3) Production of cylindrical 18650 size sealed battery A cylindrical 18650 size sealed battery A having a nominal capacity of 2.4 Ah was used in the same manner as in Example 1A, except that the positive electrode plate A and the negative electrode plate A were used. Was made.
(4) Fabrication of a sealed battery having a tabless current collecting structure A polyethylene separator is sandwiched between the produced positive electrode and negative electrode, and the exposed portion of the positive electrode and the exposed portion of the negative electrode are protruded in opposite directions from the end face of the separator. It was. Thereafter, the positive electrode, the negative electrode, and the separator were wound into a cylindrical shape.

  Subsequently, a reinforcing member was formed on the exposed portion.

  Specifically, EC, which is a solvent for the nonaqueous electrolytic solution, was heated to 50 ° C. and melted to obtain liquid EC. A 10 mm portion from the end face of the exposed portion of the positive electrode was immersed in liquid EC. Thereafter, the liquid EC was solidified by allowing to stand at room temperature. Similarly, a 10 mm portion from the end face of the exposed portion of the negative electrode was immersed in liquid EC. Thereafter, the liquid EC was solidified by allowing to stand at room temperature. Thereby, the reinforcing member was provided in the exposed part of the positive electrode and the exposed part of the negative electrode, and an electrode group could be formed.

  Thereafter, a current collecting structure was formed.

  Specifically, first, a current collector plate made of aluminum was pressed against the end face of the exposed portion of the positive electrode, and a laser beam was irradiated to the vertical and horizontal letters. Thereby, the current collector plate made of aluminum could be joined to the end face of the exposed portion of the positive electrode.

  Further, the circular portion of the nickel current collector plate was pressed against the end face of the exposed portion of the negative electrode, and the laser beam was irradiated to the vertical and horizontal letters. Thereby, the nickel current collector plate could be joined to the end face of the exposed portion of the negative electrode, and a current collector structure was formed.

The formed current collecting structure was inserted into a nickel-plated iron cylindrical case. Thereafter, the tab portion of the nickel current collector plate was bent and resistance welded to the bottom of the case. Further, the tab portion of the aluminum current collector plate was laser welded to the sealing plate, and a non-aqueous electrolyte was injected into the case. At this time, the non-aqueous electrolyte is lithium hexafluorophosphate (LiPF ₆₎ as a solute in a mixed solvent in which EC and ethyl methyl carbonate (EMC) are mixed at a mixing ratio of 1: 3 by volume. ) Was dissolved at a concentration of 1 mol / dm ³ . Thereafter, the sealing plate was crimped on the case and sealed. Thus, a sealed battery B having a nominal capacity of 5 Ah and having a tabless current collecting structure was produced.

(Example 3A)
Using a cylindrical 18650 size sealed battery A, a notebook PC as a battery-mounted device as shown in FIGS. 5 and 6 was prepared. Specifically, a battery pack 10 having an exhaust duct (connecting pipe part 10H, main pipe part 10I and connecting part 10P) and a commercially available notebook PC, the outer path (gas cooling part 10L, communication path 10Z, sparks). A notebook PC in which the trap portion 10M and the exhaust port 10Y) were formed later was prepared. A copper plate having a thickness of 1 mm was attached to the gas cooling unit 10L. The arrangement position of the copper plate was the facing wall of the wall portion to which the main pipe portion 10I is connected. A porous ceramic plate having a thickness of 1 mm (industrial ceramic honeycomb; manufactured by NGK Corporation) was attached to the spark trap portion 10M. The location of the porous ceramic plate was the facing wall of the wall to which the connecting pipe 10Z was connected. The notebook PC 11 thus manufactured was used as the battery-equipped device of Example 3A.

(Example 3B)
Using a sealed battery B having a tabless current collecting structure, an electric bicycle 14 as a battery-equipped device as shown in FIGS. 7 to 9 was prepared. Specifically, a battery pack 12 having an exhaust duct (connecting pipe portion 12H, gas cooling portion 12L, connecting portion 12P), and a commercially available electric bicycle, which has an external path (spark trap portion 12M and exhaust port 12Y) An electric bicycle formed from was prepared. A copper plate having a thickness of 1 mm was attached to the gas cooling unit 12L. The copper plate was disposed at the facing wall of the wall portion to which the connecting pipe portion 12H is connected. A porous ceramic plate (industrial ceramic honeycomb; manufactured by NGK Corporation) having a thickness of 1 mm was affixed to the spark trap portion 12M. The location of the porous ceramic plate was the facing wall of the wall portion to which the connecting portion 12P was connected. The electric bicycle 12 thus produced was used as the battery-equipped device of Example 3B.

(Example 3C)
Using a sealed battery B having a tabless current collecting structure, a hybrid electric vehicle as a battery-mounted device as shown in FIGS. 10 to 12 was prepared. Specifically, the battery pack 15 having an exhaust duct (pack main body 15A, outlet pipe 15B, concentration pipe 15C, and connection portion 15D) and a commercially available electric vehicle having an external path (gas cooling portion 16A, spark trap portion 16B). An electric vehicle having an exhaust pipe 16C) formed later was prepared. A copper plate having a thickness of 1 mm was attached to the gas cooling unit 16A. The arrangement position of the copper plate was the facing wall of the wall portion to which the connecting portion 15D was connected. A 1 mm thick porous ceramic plate (industrial ceramic honeycomb; manufactured by Nippon Gaishi Co., Ltd.) was attached to the spark trap portion 16B. The location of the porous ceramic plate was the facing wall of the wall connected to the gas cooling unit 16A. The hybrid electric vehicle thus manufactured was used as the battery-equipped device of Example 3C.

(Comparative Example 3)
A battery pack that does not have an exhaust duct (connection pipe portion 10H, main pipe portion 10I, and connection portion 10P), and a commercially available notebook PC with an external path (gas cooling portion 10L, communication passage 10Z, spark trap portion 10M, and exhaust port) 10Y) was prepared later as a notebook PC and used as a battery-equipped device of Comparative Example 3.

(Comparative Example 4)
A battery pack that does not have an exhaust duct (connecting pipe portion 12H, gas cooling portion 12L, and connecting portion 12P) and a commercially available electric bicycle that has an external path (spark trap portion 12M and exhaust port 12Y) formed later. To prepare a battery-equipped device of Comparative Example 4.

(Comparative Example 5)
A battery pack that does not have an exhaust duct (lead pipe 15B, concentration pipe 15C, and connection part 15D) and a commercially available electric vehicle, and external paths (gas cooling part 16A, spark trap part 16B, and exhaust pipe 16C) are formed later. The battery mounted device of Comparative Example 5 was prepared.

  The following evaluations were performed on each battery pack obtained in the above examples and comparative examples.

(I) Nail penetration test When the battery-equipped device is completed at an environmental temperature of 20 ° C., the maximum current when charging per cell is 0.7 It (1 It is 5 A when the battery capacity is 5 Ah), and the charging end current The battery was charged with a constant current and a constant voltage up to 4.5V by bypassing the overcharge protection circuit of the pack and the current interruption (CID) of the cell when charging was normally 4.2V. Thereafter, tests and evaluations were performed in the same manner as the nail penetration test described above.

  In Comparative Examples 3, 4 and 5, sparks and flames are emitted from various locations of the battery pack, and then the battery pack casing and the battery-equipped device are ignited and the nail puncture in the pack is not performed. Confirmed firing was confirmed. This is because the high-temperature gas containing sparks discharged from the nail penetration cell is not regulated in the flow path inside the battery pack, so that the gas is mixed with air at a high temperature and starts to burn. On the other hand, in Examples 3A, 3B, and 3C, except that white smoke was observed from the gas discharge part of the battery-equipped device, no flame or spark was observed, and the nail stab in the pack was not performed, No burning to the casing of the pack and the battery-mounted equipment was observed at all.

  It was possible to suppress similar firing to cells other than the nail puncture cells because of the effect of suppressing the mixing of air and gas by the exhaust duct or the external path and the gas released to the outside by the gas cooling part and the spark trap part. This is due to the effect of suppressing ignition.

  As shown in Examples 3A, 3B, and 3C, the same effect can be obtained regardless of whether the gas cooling unit or the spark trap unit is mounted on the battery pack or the battery-equipped device body. When it is desired to reduce the weight and size of the battery pack, it is preferable to form a gas cooling part and a spark trap part on the battery-equipped device body side.

  In this way, by reducing the temperature of the high-temperature gas released from the inside of the battery and releasing it to the outside of the battery-equipped device, the gas does not burn and does not cause damage to the battery pack or similar burning to other batteries. A battery-equipped device can be realized.

  Furthermore, a cylindrical lithium ion secondary battery having a diameter of 32 mm and a height of 120 mm, which is a sealed battery having a tabless current collecting structure of the same design as the batteries used in Examples 3B and 3C, is shown in FIG. A duct and a battery having connection parts as shown in FIG. 17 were produced, and the same gas cooling part and spark trap part as those used in Example 3B were connected.

  When these were used and evaluated by the same method as in the nail penetration test, it was confirmed that there was a similar effect of suppressing sparks and flames from the gas discharge part. It was also confirmed that there was no leakage of sparks and flames from the connection part. As described above, it was confirmed that the installation and production can be facilitated without adversely affecting the safety by connecting the battery and the duct with the detachable connecting member.

  The battery pack according to the present invention does not cause damage or burning of the battery pack even when a high-temperature gas is discharged from the battery when the battery in the battery pack is abnormal. A battery pack having excellent safety can be provided.

It is a perspective view which shows the whole structure of the battery pack which concerns on embodiment of this invention. It is a figure which shows one set of battery and exhaust duct which are arrange | positioned at the top. It is a perspective view which expands and shows the vicinity of a gas cooling part and a spark trap part. It is sectional drawing which shows the structure of a battery. It is a figure which shows the structure of notebook type PC which is a battery mounting apparatus. It is a disassembled perspective view which shows the structure of the battery pack mounted in the notebook type PC of FIG. It is a figure which shows the structure of the electric bicycle which is a battery mounting apparatus. It is a disassembled perspective view which shows the structure of the battery pack mounted in the electric bicycle of FIG. It is a top view of the assembled battery of the battery pack of FIG. It is the side schematic diagram which expands and shows a part of composition of a hybrid type electric car which is a battery loading equipment. It is a front view which shows the structure of the battery pack mounted in the electric vehicle of FIG. It is a figure which decomposes | disassembles and shows the pack body of the battery pack of FIG. It is sectional drawing which shows the junction part of the gas discharge | release part and duct of a battery. It is sectional drawing which shows the junction part of the gas discharge | release part and duct of a battery. It is sectional drawing which shows the junction part of the gas discharge | release part and duct of a battery. It is sectional drawing which shows the junction part of the gas discharge | release part and duct of a battery. It is sectional drawing which shows the junction part of the gas discharge | release part and duct of a battery.

1A, 1B Battery pack housing 1C Exhaust duct 1D Battery assembly 1E Connection plate 1F Battery terminal 1G Connection lead 1H Connection pipe part 1I Main pipe part 1L Gas cooling part 1M Spark trap part 1N Connecting pipe 1P Exhaust port 2A Positive electrode plate 2B Negative electrode plate 2C Separator 2D Electrode plate group 2E Positive electrode lead current collector 2F Negative electrode lead current collector 2G Bottomed case 2H Sealing plate 2I Filter 2J Outer gasket

Claims (6)

A battery pack having a configuration in which a battery is housed in a housing, having a path through which gas discharged from the battery is circulated, and configured to reduce the temperature of the gas through the path and discharge the gas to the outside. ,
The gas flow is combined into one, the flow is regulated so that it does not disperse, and a duct that is sealed so as not to leak gas is provided as the path,
Cross-sectional area of the pathway is the battery capacity 1Ah per 0.5 mm ² or more with a gas discharge portion communicating with the path, and 15 mm ² Ri following ranges der,
Wherein the path, the battery pack that contains the bent portion for bending a flowing direction of gas.   2. The battery pack according to claim 1, wherein the path allows the gas to flow so that the flow rate of the gas does not decrease below a predetermined value. The battery pack according to claim 1, wherein heat exchange means or heat absorption means for reducing the temperature of the gas is provided in the path. The battery pack according to claim 1, wherein means for trapping sparks generated in the gas is provided in the path. The battery pack according to claim 1 or 2, wherein a gas discharge part of each battery is connected to the path so that gases from a plurality of batteries can flow into the path. The battery pack according to claim 1 or 2, wherein the battery and the path are configured to be detachable from each other.

Images