JP4977475B2 - Case for film exterior electrical device - Google Patents

Description

  The present invention relates to a film-covered electric device case for storing a film-covered electric device in which an electric device element represented by a battery or a capacitor is stored in an outer film.

  In recent years, the development of electric vehicles and hybrid electric vehicles (hereinafter also simply referred to as “electric vehicles etc.”) equipped with a battery for driving a motor has been rapidly advanced. Naturally, batteries mounted on electric vehicles and the like are also required to be lightweight and thin in order to improve the handling characteristics and travel distance of the electric vehicle. In order to make the battery lightweight and thin, a film-clad battery using a laminate material made of a thin film has been developed for its outer package. In general, a laminate material has a structure in which both surfaces of a thin metal layer such as aluminum are covered with a thin resin layer, and is resistant to acids and alkalis, and is lightweight and flexible.

  A film-clad battery in which a power generation element is covered with a laminate material has an advantage of being lightweight. However, since it has low rigidity and is easily affected by vibrations and shocks, it is necessary to solve these problems when mounted on an electric vehicle or the like. In order to solve this problem, as disclosed in Japanese Patent Application Laid-Open No. 10-012278, a technique for sandwiching and fixing a film-clad battery in a case is conventionally known.

  In order to obtain a battery suitable for an electric vehicle or the like, it is desired to increase the capacity and output of the battery. For this reason, the film exterior batteries contained in a plurality of cases are stacked and electrically connected, that is, a so-called assembled battery is formed. At this time, for the purpose of cooling each film-clad battery, the case in which the film-clad battery is put is shaped so that an appropriate ventilation gap is formed between the film-clad batteries when it is assembled into an assembled battery. ing. When such an assembled battery is mounted on an electric vehicle or the like, normally, the air taken in from the passenger compartment is introduced as cooling air into the air gap between the film-clad batteries, and the cooling air heated through the air gap is heated. Is configured to be discharged outside the vehicle.

  The film-clad battery is one in which a power generation element is inserted between facing laminate materials, and the periphery of the laminate material is welded by thermal welding. In addition, the heat-sealed portion of the film-clad battery is provided with a gas discharge portion in which a part of the heat-sealed portion is peeled off at a pressure lower than that of other portions.

  When a voltage outside the standard range is applied to the battery during use of the battery, gas species may be generated due to electrolysis of the electrolyte solvent, and the internal pressure of the battery may increase. Furthermore, even when the battery is used at a high temperature outside the standard range, gas species are generated due to decomposition of the electrolyte salt or the like. For this reason, basically, it is ideal to use a battery within a standard range so as not to generate gas. However, if the battery control circuit fails for some reason and an abnormal voltage is applied, or the surroundings become abnormally hot for some reason, a large amount of gas is generated in some cases.

  Such generation of gas inside the battery causes an increase in the internal pressure of the battery. In order to prevent the internal pressure from excessively rising and the battery from exploding, many batteries using metal cans as exterior materials have a pressure safety valve that allows gas to escape outside the battery when the internal pressure of the battery increases. . However, it is structurally difficult to provide a pressure safety valve in a film-clad battery using a film as a packaging material. In a film-clad battery, if the internal pressure rises too much, the film expands, eventually rupturing the packaging material, and gas is ejected from that location. However, since it is not possible to specify where the rupture occurs, depending on the ruptured portion, there may be an adverse effect on surrounding equipment.

  Therefore, in the film-clad battery, in order to eliminate such a problem due to the generation of gas inside the battery, the gas discharge part as described above is provided in the heat fusion part. Further, as shown in FIG. 1, a gas discharge port 103 is formed in the case 102 of the film-clad battery 101 so as to surround the gas discharge part 104 provided in the film-clad battery 101. In addition, when it mounts in an electric vehicle etc. in the state which laminated | stacked the film-clad battery | casing containing a case, and was set as the assembled battery, the gas exhaust port 103 will be connected with the divided exhaust gas passage for discharging | emitting gas out of a vehicle.

  However, in the case of the conventional case shape as shown in FIG. 1, the gas discharge port 103 is only formed so as to surround the gas discharge portion 104 of the film-clad battery 101, and the case is overlapped to form an assembled battery. At this time, the opening 102a which becomes a ventilation gap (cooling passage) is communicated between the film-clad batteries. For this reason, when gas is generated due to an abnormality in the battery, if the gas is not quickly discharged into the exhaust gas passage through the gas discharge port 103 provided in the case, it may leak into the opening 102a which is the cooling passage. is there. Since this cooling passage is connected to the vehicle interior, if gas enters the gas, the gas flows backward into the vehicle interior, which may adversely affect the human body.

  The present invention has been made in view of the above-described problems of the prior art, and it is an object of the present invention to provide a film-covered battery case that reliably discharges gas generated when a battery is abnormal to the exhaust gas passage and does not affect the human body. .

  To achieve the above object, the present invention accommodates a film-clad electrical device having a chargeable / dischargeable electrical device element, an exterior film sealed with the electrical device element sandwiched therebetween, and a gas discharge portion provided in the exterior film. The present invention relates to a case for a film-covered electrical device. In this case, an opening is formed in a region corresponding to the electric device element, and the film exterior provided to connect the frame member holding the peripheral edge of the electrical device element in the exterior film and the opposite sides of the frame member. An exhaust gas passage section for guiding the gas discharged from the gas discharge section of the electric device to the outside. And the sealing material which divides an exhaust gas passage part from an opening by sticking to the surface of a film exterior electric device is provided in the both-sides edge of the surface which becomes the film exterior electrical device side of an exhaust gas passage part. ing.

  Moreover, it is preferable that the sealing material is provided along the both side edges of the exhaust gas passage portion also on the outer surface of the exhaust gas passage portion.

  In the invention configured as described above, the exhaust gas passage portion is completely partitioned from the opening portion serving as a cooling passage (ventilation gap). Thus, even when gas is generated from the gas discharge portion provided in the film-covered electrical device when the battery is abnormal, it does not leak into the opening serving as a cooling passage. Therefore, the gas from the gas discharge unit is reliably discharged to the exhaust gas passage that guides the gas to the outside of the vehicle. In addition, since gas does not enter the opening that is the cooling passage connected to the passenger compartment, there is no influence on the human body.

  In the case for the film-clad electrical device, it is considered that the sealing material is a foamable resin or an ultraviolet curable resin.

  As described above, according to the present invention, it is possible to provide a case for a film-clad battery that reliably discharges gas generated when a battery is abnormal to the exhaust gas passage and does not affect the human body.

It is a perspective view which shows the shape of the conventional case containing the film-clad battery. It is an external appearance perspective view of the film-clad battery applicable to this invention. It is a disassembled perspective view of an example of the cell case of this invention which accommodates a film-clad battery. It is a perspective view of the cell case which accommodated the film exterior battery. FIG. 5 is a cross-sectional view taken along the line X-X ′ of FIG. 4, illustrating a film-clad battery and a cell case that houses the film-clad battery. It is typical sectional drawing which shows the state which accumulated the cell case which accommodated the film exterior battery of FIG. 5 for the battery assembly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 shows an external perspective view of the film-clad battery of this embodiment.

  The film-clad battery 1 of the present embodiment is formed by superposing a power generation element 2 having a positive electrode side active electrode, a negative electrode side active electrode, and an electrolyte, a metal film such as aluminum, and a heat-fusible resin film. And a laminate film 7. The film-clad battery 1 has a structure in which the power generation element 2 is sealed with two laminated films 7. That is, when the power generating element 2 is hermetically sealed with the two laminate films 7, the three sides of the heat-sealed portion 7 a that is the four sides of the laminate film 7 are first heat-sealed to form a bag shape. Then, the internal air is exhausted from the remaining one side that is open and evacuated, and then the remaining one side heat-sealed portion 7a is heat-sealed.

  The power generation element 2 of the film-clad battery 1 may be a laminated type composed of a positive electrode side active electrode and a negative electrode side active electrode laminated via a separator. Alternatively, a positive electrode side active electrode and a negative electrode side active electrode are alternately stacked by stacking a belt-like positive electrode side active electrode and a negative electrode side active electrode through a separator, winding this, and then compressing it flatly. It may be a wound type having a different structure.

  In addition, as the power generation element 2, any power generation element used for a normal battery is applicable as long as it includes a positive electrode, a negative electrode, and an electrolyte. A power generation element in a general lithium ion secondary battery includes a positive electrode plate in which a positive electrode active material such as lithium-manganese composite oxide or lithium cobaltate is applied on both sides of an aluminum foil, and a carbon material that can be doped or dedoped with lithium. Is formed by impregnating a negative electrode plate coated with copper foil on both sides of a copper foil with a separator interposed therebetween and impregnating an electrolytic solution containing a lithium salt. Other examples of the power generation element 2 include power generation elements of other types of chemical batteries such as nickel metal hydride batteries, nickel cadmium batteries, lithium metal primary batteries or secondary batteries, and lithium polymer batteries. Furthermore, the present invention provides an external device that stores electrical energy and generates gas by chemical reaction or physical reaction, such as a capacitor element exemplified by a capacitor such as an electric double layer capacitor and an electrolytic capacitor. The present invention can also be applied to an electric device sealed with a film.

  From the heat-sealing part 7a in the short direction of the film-clad battery 1, the positive electrode terminal 3 connected to the positive electrode side active electrode and the negative electrode terminal 4 connected to the negative electrode side active electrode extend opposite to each other. I'm out. Aluminum is often used as the positive electrode terminal 3. Further, copper or nickel is often used as the negative electrode terminal 4 due to its electrical characteristics. Hereinafter, the positive electrode terminal 3 and the negative electrode terminal 4 may be collectively referred to as electrodes.

  A part of the heat-sealed portion 7a in the longitudinal direction of the film-clad battery 1 is made weaker in heat-sealing strength than the other portions, and the fusion is peeled off at a lower pressure than the other portions when the gas is generated. The gas discharge section 8 is provided.

  FIG. 3 shows an exploded perspective view of a cell case that houses a film-clad battery.

  The cell case 10 surrounding the periphery of the film-clad battery 1 has a first frame 11 and a second frame 12, and the film-clad battery 1 is sandwiched between the first and second frames 11 and 12 by a clamping surface. . Each of the frames 11 and 12 has a frame shape. An opening 13 is formed at a location corresponding to the power generation element 2 of the film-clad battery 1.

  The first frame 11 is a rectangular frame composed of two long sides 11a facing each other and two short sides 11b formed substantially orthogonal to each of the long sides 11a and facing each other. Each long side 11a is connected by an exhaust gas passage portion 11c for guiding the gas discharged from the gas discharge portion 8 of the film-clad battery 1 to the outside. In this embodiment, since the gas discharge part 8 of the film-clad battery 1 is formed in the approximate center of the heat-fusion part 7a, the exhaust gas passage 11c is also formed in the approximate center of the long side 11a. The opening 13 is divided into two. Further, a cutout 11d for forming a gas discharge port 16 is formed at one end of the long side 11a and at one end of the exhaust gas passage portion 11c.

  Each short side 11b of the first frame 11 is formed with a notch 11e for extending the electrode of the film-clad battery 1 stored in the cell case 10 to the outside.

  Sealing portions 30 for blocking communication of the exhaust gas passage portion 11c with the opening 13 are provided on both side edges of the surface of the exhaust gas passage portion 11c facing the film-clad battery 1 as described later. Yes. Further, the sealing portion 30 is provided along both side edges of the exhaust gas passage portion 11c also on the outer surface of the exhaust gas passage portion 11c.

  As the sealing material 30, a urethane-based or butyl-based foamable resin is preferable. In the case where the encapsulant 30 is cured after being filled in the storage portion 15, it is more preferable to use an ultraviolet curable resin instead of a thermosetting resin. This is because, in the case of an ultraviolet curable resin, the resin is cured by irradiating ultraviolet rays, so that the film-covered battery 1 is not adversely affected by heat during curing.

  The basic structure of the second frame 12 is the same as that of the first frame 11. The second frame 12 is also a rectangular frame composed of two long sides 12a and two short sides 12b, and a notch 12d for forming a gas discharge port 16 is formed on one of the long sides 12a. Further, the second frame 12 is provided with an electrode holding portion 12e that fits into the notch 11e of the first frame 11. The electrode holding portion 12e is formed to have a thickness that allows an opening through which the electrode can be extended in a state of being fitted into the notch 11e.

  Next, a procedure for storing the film-clad battery 1 in the cell case 10 will be described.

  First, the film-clad battery 1 is sandwiched between the long side 11a of the first frame body 11 and the long side 12a of the second frame body 12 in the longitudinal direction of the heat-sealing portion 7a. Is sandwiched between the short side 11b and the short side 12b. That is, heat fusion is performed on the clamping surface between the first frame body 11 and the second frame body 12 (the surface that faces when the first frame body 11 and the second frame body 12 are arranged to face each other). The part 7a is clamped. At this time, the gas discharge unit 8 is positioned at the gas discharge port 16.

  FIG. 4 is a perspective view of the film-clad battery 1 housed and held in the cell case 10. In FIG. 4, the electrodes 3 and 4 are shown in a bent state. FIG. 5 is a cross-sectional view taken along the line X-X ′ of FIG. 4, and is a schematic cross-sectional view of the film-clad battery 1 and the cell case 10 that houses the film-clad battery 1.

  As shown in FIG. 4 and FIG. 5, since the portion exposed at the opening 13 of the film-clad battery 1 is open to the atmosphere, the cooling air is directly applied to the surface of the film-clad battery 1 for cooling. Therefore, good cooling characteristics can be obtained. When a plurality of cell cases 10 in which the film-clad battery 1 is stored are stacked to form an assembled battery, the opening 13 serves as a ventilation gap as a cooling passage. Moreover, the sealing material 30 which closely_contact | adheres to the surface of the film-clad battery 1 is provided in the both-sides edge of the surface which opposes the film-clad battery 1 of the waste gas passage part 11c. By this sealing material 30, the exhaust gas passage portion 11c becomes a passage completely defined from the opening 13 on the first frame body 11 side (see FIG. 5).

  As described above, the exhaust gas passage portion 11c is completely partitioned from the opening 30 serving as a cooling passage (ventilation gap), so that gas is generated from the gas discharge portion 8 provided in the film-covered battery 1 when the battery is abnormal. However, at least the opening 13 on the first frame 11 side does not leak.

  As described above, with respect to the opening 13 on the first frame 11 side where the exhaust gas passage portion 11c is provided, the gas discharged from the gas discharge portion 8 of the film-clad battery 1 is completely contained in the exhaust gas passage portion 11c. And can be prevented from leaking to the opening 13 on the first frame 11 side. On the other hand, also regarding the opening 13 on the second frame 12 side where the exhaust gas passage portion 11c is not provided, the gas discharged from the gas discharge unit 8 leaks to the opening 13 on the second frame 12 side. Can be considered. Therefore, as shown in FIG. 5, the sealing material 30 is also provided on both side edges of the outer surface of the exhaust gas passage portion 11c, so that the gas discharged from the gas discharge portion 8 can be opened on the second frame 12 side. 13 is prevented from leaking out.

  Specifically, as shown in FIG. 6, when the cell case 10 in which the film-clad battery 1 is stored is overlapped, the exhaust gas passage portion 11 c provided in the opening 13 on the first frame 11 side is adjacent. The cell case 10 is disposed in the opening 13 on the second frame 12 side. At this time, the sealing material 13 provided on the outer surface of the exhaust gas passage portion 11c is in close contact with the surface of the film-clad battery 1 in the opening 13 on the second frame body 12 side of the adjacent cell case 10. For this reason, the exhaust gas passage portion 11c disposed in the opening 13 on the second frame 12 side is also a passage completely partitioned from the opening 13 on the second frame 12 side. Thereby, even if gas is generated from the gas discharge part 8 of the film-clad battery 1 when the battery is abnormal, it does not leak into the opening 13 on the second frame 12 side.

  By the above, the gas from the gas discharge part 8 is reliably discharged | emitted to the exhaust gas path which guides gas out of a vehicle through the exhaust gas channel part 11c and the gas exhaust port 16 which were provided in the cell case 10. FIG. Further, since the gas does not enter the opening 13 that is a cooling passage connected to the vehicle interior, the influence on the human body can be eliminated.

Claims (5)

A case for a film-clad electrical device that houses a film-clad electrical device having a chargeable / dischargeable electrical device element, an exterior film sealed with the electrical device element sandwiched therebetween, and a gas discharge portion provided in the exterior film. And
An opening is formed in a region corresponding to the electrical device element, and a frame member that holds a peripheral edge of the electrical device element in the exterior film;
An exhaust gas passage portion provided so as to connect opposite sides of the frame member, and for guiding the gas discharged from the gas discharge portion of the film-covered electrical device to the outside, and
Sealing material that partitions the exhaust gas passage portion from the opening by closely contacting the surface of the film-covered electrical device on both side edges of the surface that faces the film-covered electrical device of the exhaust gas passage portion A film-covered case for an electric device with a film.   2. The film-covered electrical device case according to claim 1, wherein a sealing material is provided along both side edges of the exhaust gas passage portion also on the outer surface of the exhaust gas passage portion.   The film-covered electrical device case according to claim 1, wherein a gas discharge port is formed at one end of the exhaust gas passage portion.   The film-covered electrical device case according to any one of claims 1 to 3, wherein the sealing material is a foamable resin.   The case for film-clad electrical devices according to any one of claims 1 to 3, wherein the sealing material is an ultraviolet curable resin.

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