JP5815793B2 - Film-covered electrical device case and method for producing the film-covered electrical device case - 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 is stored in an outer film, represented by a battery or a capacitor, and a method for manufacturing the film-covered electric device case.

  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 lighter and thinner, a film-clad battery using a laminate material in which a metal layer such as aluminum and a heat-weldable resin layer are laminated on the outer package via an adhesive layer to form a thin film. Has been developed. 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 is lightweight, but has low rigidity and is easily affected by vibration and impact. Therefore, when mounted on a vehicle, it is necessary to solve these problems. In order to solve this problem, as disclosed in Patent Document 1, a technique for sandwiching and fixing a film-clad battery in a case is conventionally known. This method is advantageous in terms of securing rigidity or protecting from impact, but it is difficult to absorb vibration.

  As a method of absorbing vibration, there is a method of compressing and using a low hardness rubber. However, even with a low hardness rubber, it is known that the reaction force when the rubber is compressed rises abruptly compared to the amount of compressive deformation, and it is difficult to obtain good vibration absorption characteristics. It was. In the case of rubber, the weight may increase.

  On the other hand, Patent Document 2 discloses a module battery in which a film-clad battery is housed in a case and a potting material is filled between the case and the film-clad battery.

JP-A-10-012278 JP 2004-39485 A

  The structure disclosed in Patent Document 2 does not cause the reaction force to rise abruptly like rubber, and can be reduced in weight compared to rubber. However, in the structure disclosed in Patent Document 2, the potting material is filled between the case and the battery so as to cover the entire battery including the power generation element. For this reason, a problem may occur in the heat dissipation characteristics. That is, the potting material functions as a heat insulating material, and the heat from the power generation element cannot be radiated to the outside, and the battery is overheated. As a result, the battery life may be shortened.

  In addition, although it is lighter than rubber, connecting a plurality of batteries filled with a potting material without a gap between the case and the battery to form an assembled battery will also increase the weight.

  The present invention has been made in view of the above problems, and a case for a film-covered electrical device capable of obtaining good vibration absorption characteristics and cooling characteristics while suppressing an increase in weight, and the film-covered electrical device. An object of the present invention is to provide a manufacturing method for an industrial case.

  The film-covered electrical device case of the present invention is a film-wrapped electrical device case that houses a film-covered electrical device having a chargeable / dischargeable electrical device element and an exterior film that covers the electrical device element. A pair of frame members having an opening in a region corresponding to the electric device element, and a pair of holding members that are provided on the clamping surfaces of the pair of frame members and hold the film-covered electric device The pair of holding materials are opposed to each other with the film-clad electrical device interposed therebetween, and the portions of the holding material facing each other have the same shape.

  The film-covered electrical device case of the present invention configured as described above has a holding material on the holding surface of the frame member having an opening, and this holding material holds the film-covered electrical device. That is, since the holding material is not provided in the opening, the heat generated by the electric device element is not stored, and when the cooling air is supplied, the holding material may inhibit cooling. Absent. Further, since the film-covered electric device is held by the holding material, it is possible to prevent external impact or vibration from being transmitted to the film-covered electric device. Further, the weight can be reduced by the amount of the holding material in the electric device element portion.

  The method for producing a film-covered electrical device case of the present invention is a method for manufacturing a film-covered electrical device case that houses a film-covered electrical device having a chargeable / dischargeable electrical device element and an exterior film that covers the electrical device element. A frame member forming step of forming a pair of frame members having openings in regions corresponding to the electrical device elements, the frame member forming step facing each other on the mutually facing surfaces of the pair of frame members A holding material forming step of forming a pair of holding materials having the same shape.

  According to the method for manufacturing a film-covered electrical device case of the present invention as described above, since the holding material can be formed simultaneously with the forming of the frame member, a step of attaching the holding material separately can be omitted. . Moreover, since the manufacturing method of this invention shape | molds a holding material, the freedom degree of the shape of a holding material becomes high.

  According to the present invention, the holding member is provided only on the holding surface of the frame member, thereby holding the film-covered electric device, and the holding member is not provided in the opening portion. Vibration absorption characteristics and heat dissipation characteristics can be obtained.

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 sectional drawing of the cell case which accommodated the film-clad battery and this film-clad battery. It is a perspective view of the cell case which accommodated the film exterior battery. It is a perspective view which shows the example of the other shape of a holding material. It is a perspective view of the film-clad battery for showing the example of arrangement | positioning of a holding material. It is sectional drawing which shows the cross-sectional example of the holding | maintenance material comprised by the waveform and recessed part shape | molded by the two-color molding method. It is sectional drawing which shows the cross-sectional example of the holding | maintenance material comprised by the convex part which mutually shape | molded by the two-color molding method.

  An embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 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 laminate films 7. That is, in the film-clad battery 1 of the present embodiment, among the heat-sealed portions 7a that are the four sides of the laminate film 7, first, three sides are heat-sealed to form a bag shape. The internal air is exhausted from the remaining one side opened by vacuuming. Finally, the power generating element 2 is hermetically sealed by the two laminated films 7 by heat-sealing the remaining one-side heat-sealing portion 7a.

  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, in the power generation element 2, the belt-like positive electrode side active electrode and the negative electrode side active electrode are stacked via a separator, wound, and then compressed into a flat shape, whereby the positive electrode side active electrode and the negative electrode side active electrode are A wound type having a structure in which layers are alternately stacked may be used.

  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. The power generation elements in a typical lithium ion secondary battery include a positive electrode plate in which a positive electrode active material such as lithium-manganese composite oxide and lithium cobaltate is applied on both sides of an aluminum foil, etc., and carbon that can be doped and dedoped with lithium. A negative electrode plate coated with a material on both sides of a copper foil or the like is opposed to each other with a separator interposed between them and impregnated with 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 can also be applied to an electric device in which an electric device element that stores electric energy therein, such as a capacitor such as an electric double layer capacitor or an electrolytic capacitor, is sealed with an exterior film.

  The power generation element 2 has a plurality of positive electrode side active electrodes and a plurality of negative electrode side active electrodes, and these are alternately laminated so that the outermost side becomes the negative electrode side active electrode (see FIG. 3). Separators are respectively disposed between the positive electrode side active electrode and the negative electrode side active electrode and on the outer side of the outermost negative electrode side active electrode. Tabs 2a are respectively provided so as to protrude from one side of the positive electrode side active electrode and the negative electrode side active electrode. The tab 2a of the positive electrode side active electrode and the tab 2a of the negative electrode side active electrode are provided at different positions so that the tabs 2a of the positive electrode side active electrode and the tabs 2a of the negative electrode side active electrode overlap each other.

  The tabs 2a of the positive electrode side active electrodes and the tabs 2a of the negative electrode side active electrode are ultrasonically welded together to form the positive electrode current collector 3a and the negative electrode current collector 4a, respectively. The positive electrode terminal 3 is connected to the positive current collector 3a, and the negative electrode terminal 4 is connected to the negative current collector 4a.

  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 for the positive electrode terminal 3, and copper or nickel is often used for 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 gas exhausted so that the heat-sealing strength is weaker than that of other portions and the fusion is peeled off at a lower pressure than the other portions. A part 8 is provided.

  If a voltage outside the standard range is applied to the battery during use of the battery, gas 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 may be generated due to decomposition of the electrolyte salt. Basically, it is ideal to use the battery within the standard range so that gas is not generated, but the battery control circuit fails for some reason and abnormal voltage is applied, or for some reason If the surroundings become abnormally hot, a large amount of gas may be 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. If the internal pressure is too high in a film-clad battery, the film expands and eventually the exterior material ruptures and gas is emitted from that location, but it is not possible to specify where the rupture occurs, so depending on the location It may adversely affect surrounding equipment.

  Therefore, in the film-clad battery 1, the gas discharge part 8 as described above is provided in the heat-sealing part 7 a in order to eliminate such problems caused by the generation of gas inside the battery.

  FIG. 2 shows an exploded perspective view of a cell case that houses a film-clad battery. FIG. 3 shows a cross-sectional view of a film-clad battery and a cell case that houses the 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, and 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 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 notch 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 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. Each short side 11b is formed with a concave storage portion 15 for holding a holding member 30 described later. The storage portion 15 includes an electrode corresponding portion 15a corresponding to a portion where the electrode of the short-side heat fusion portion 7a of the film-covered battery 1 extends, and corners corresponding to the corner portions of the film-covered battery 1 on both sides. Part corresponding part 15b. In the present embodiment, the corners of the film-clad battery 1 mean the four corners of the film-clad battery 1. That is, the corner is an area where the laminate film 7 is particularly easily damaged (area surrounded by A in FIGS. 1 and 2). Since each corner has both end portions 3a 'and 4a' in the width direction (B direction in FIG. 2) of the current collecting portions 3a and 4a, the corner portions are easily damaged.

  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. Each short side 12b is formed with a storage portion 15 including an electrode corresponding portion 15a and a corner corresponding portion 15b. Unlike the first frame 11, the second frame 12 is not provided with the exhaust gas passage 11c. The second frame body 12 is provided with an electrode holding portion 12e that fits into the notch 11e of the first frame body 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.

  The holding material 30 is preferably a urethane-based or butyl-based foamable resin. In addition, when it is made to harden | cure after filling the holding | maintenance material 30 in the accommodating part 15, it is more preferable to use the ultraviolet curable resin for the holding material 30 instead of a thermosetting resin. This is because in the case of an ultraviolet curable resin, the film is cured by irradiating with ultraviolet rays, so that the film-clad battery 1 is not affected by heat during curing.

  Next, a procedure for storing the film-clad battery 1 in the cell case 10 when using the pre-cured holding material 30 will be described.

  First, the holding material 30 formed in accordance with the shape of the storage portion 15 is fitted into the storage portions 15 in a total of four locations, the first frame body 11 and the second frame body 12. The holding material 30 may be fixed to the storage unit 15 with a double-sided tape or an adhesive.

  Next, the heat-sealed portion 7a in the longitudinal direction of 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, and The heat-sealing part 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.

  As shown in FIG. 3, the holding material 30 housed in the housing portion 15 is in close contact with the surfaces of the heat-sealing portion 7 a and the close-contact portion 7 b and holds the film-clad battery 1 in the cell case 10. The holding material 30 is appropriately compressed at the heat-sealing portion 7a and the close-contact portion 7b. In addition, the heat sealing | fusion part 7a which is compressing the holding material 30 is a thing of the transversal direction where the electrode of the film-clad battery 1 is extending among four sides. Further, the close contact portion 7b refers to a region where the laminate film 7 is in close contact with the current collecting portions 3a and 4a by vacuum drawing although not thermally fused.

  The holding material 30 covers the corners of the film-clad battery 1 in this state. Note that the holding member 30 does not hold the main body portion of the power generation element 2 facing the opening 13. That is, the holding material 30 covers the corners where cracks or the like are likely to occur, but does not cover the main body portion of the power generation element 2. That is, the film-clad battery 1 is held in the vicinity of the electrode by the holding material 30, but the main body portion of the power generation element 2 is open to the atmosphere. The holding member 30 that holds the film-clad battery 1 in this way prevents external shock from being transmitted to the film-clad battery 1 and absorbs vibration. Further, the holding material 30 fills a gap formed between the electrode and the opening from which the electrode extends. If the cooling air supplied to the opening 13 leaks from the gap, the cooling efficiency of the power generating element 2 is lowered. However, since the holding member 30 fills the gap, it is possible to prevent the cooling efficiency of the power generation element 2 from being lowered due to cooling air leakage.

  FIG. 4 is a perspective view of the film-clad battery 1 housed and held in the cell case 10. Each electrode 3 and 4 is shown in a bent state. As shown in FIG. 4, the holding material 30 does not exist on the surface of the main body portion of the power generation element 2. Therefore, the heat generated by the power generation element 2 can be efficiently radiated to the outside without the holding material 30 functioning as a heat storage material. Moreover, since the main-body part of the electric power generation element 2 is open | released by air | atmosphere at the opening part 13, since a cooling wind can be directly applied to the electric power generation element 2 and it can cool, it can obtain a favorable cooling characteristic. Further, since the holding material 30 does not cover the main body portion of the power generation element 2, the weight is reduced accordingly. Furthermore, since the holding material 30 is provided only in the portion corresponding to the electrode as described above, and is not provided in the portion of the gas discharge port 16, the gas discharged from the gas discharge portion 8 by the holding material 30 is provided. Exhaust is not hindered.

  As shown in FIG. 5, the shape of the holding member 30 may be one that holds both end portions of the electrode, that is, only the corner portion of the battery that is particularly easily damaged, and does not hold the center portion of the electrode. In this case, further weight reduction can be achieved.

  In the above-described example, the holding material 30 is disposed in the heat-sealed portion 7a in the short direction in which the electrodes extend, but the present invention is not limited to this, and as shown in FIG. The holding material 30 may be arranged at the position 7c of the longitudinal heat fusion portion 7a that does not hinder the exhaust of the gas from the gas discharge portion 8. That is, the holding material 30 may be configured to be provided in a region other than the gas discharge port 16 of the cell case 10. In this case, the gas can be discharged in a desired direction, and the number of locations that are held by the holding material 30 increases, so that the number of locations that absorb vibration increases, so the vibration absorption characteristics are further improved.

  In the above-described example, the holding material 30 is formed separately from the cell case 10, and the film-clad battery 1 is inserted into the storage unit 15 before being stored in the cell case 10, or is filled. However, the present invention is not limited to this. That is, it may be formed by using a so-called two-color molding method in which the holding material 30 is formed at the same time as the cell case 10 is formed.

  In the case of the method of filling the holding material, a test shot for obtaining an optimum filling amount and filling state is required. In addition to the step of molding the cell case, a step of filling the holding material is required. Furthermore, in the case of the filling method, the shape of the holding material depends on the shape of the region to be filled, and cannot be a free shape. Further, the method of separately forming the holding material requires a step of fitting the holding material into the storage portion.

  On the other hand, in the case of a manufacturing method in which the holding material is molded simultaneously with the cell case by the two-color molding method, not only can the molding process be simplified, but the degree of freedom of the shape of the holding material can be increased.

  7A and 7B show examples of the cross-sectional shape of the holding material molded by the two-color molding method.

  When it is desired to grip the electrode with a strong local force, for example, the holding materials 31 and 32 shown in FIG. 7A may be used. The holding member 31 has a corrugated contact portion 31a that contacts the electrode portion. On the other hand, the holding member 32 has a concave portion 32a shaped to receive the corrugated contact portion 31a. It is possible to increase the gripping force by forming such shapes that mesh with each other.

  Further, when it is desired to reliably prevent the cooling air for cooling the power generating element 2 from escaping from the gap between the electrode and the cell case 10, for example, a holding material 33 having a shape as shown in FIG. 7B is formed. Also good. By using the holding material 33 in which the convex portions 33a oppose each other, the degree of adhesion of the holding material 33 to the electrode portion is increased, thereby preventing the cooling air from escaping from the gap between the electrode and the cell case 10. .

  Moreover, it can also be expected that the cost is increased by making the upper and lower shapes the same as the holding material 33.

  In addition, when the cell case 10 and the holding materials 31 to 33 are formed by the two-color molding method, the material of the cell case 10 may be, for example, PA (polyamide) 6 or PA66, and the material of the holding material may be PA11.

  In the example described above, the first frame body 11 and the second frame body 12 sandwich the heat-sealed portion 7a of the film-clad battery 1 on the clamping surface, and the holding material 30 holds the film-clad battery 1. Although the structure to perform was shown in the example, the film-clad battery 1 may be configured to be held in the cell case 10 only by the holding material 30.

  Moreover, although the holding material 30 demonstrated the example accommodated in the accommodating part 15 in the example mentioned above, it does not form a recessed part like the accommodating part 15, but the 1st frame 11 and the 2nd frame. The holding material 30 may be provided on the holding surface for holding the film-clad battery 1 with the body 12.

  As described above, the cell case 10 of the present embodiment has a configuration in which the film-clad battery 1 is sandwiched so that the holding material 30 covers the corners of the film-clad battery 1 but does not cover the main body portion of the power generation element 2. ing. By this holding method, not only can the body portion of the power generating element 2 be suitably cooled, but also the film-covered battery 1 can be held while absorbing vibrations well, and further weight reduction can be achieved. . Further, when the holding material 30 is provided so as to fill a gap formed between the electrode and the opening from which the electrode extends, the cooling air can be prevented from leaking from the gap, and the power generation element 2 can be cooled. It can prevent that efficiency falls.

Claims (9)

A film-covered electrical device case containing a film-covered electrical device having a chargeable / dischargeable electrical device element and an exterior film covering the electrical device element,
A pair of frame members that sandwich the film-covered electrical device on a sandwiching surface and have an opening in a region corresponding to the electrical device element;
A pair of holding members that are provided on the clamping surfaces of the pair of frame members and hold the film-covered electrical device;
The pair of holding materials are opposed to each other across the film-covered electrical device, and the mutually facing portions of the holding material have the same shape.
Case for film-covered electrical devices. 2. The film-covered electrical device case according to claim 1, wherein the holding material is disposed in a region other than a gas discharge port for exhausting a gas generated inside the film-wrapped electrical device. The holding member holds the corners of the film-covered electrical device rectangular, film-covered electrical device for case according to claim 1 or 2.
The case for film-covered electric devices according to claim 3 , wherein the holding material further holds a portion corresponding to an electrode of the film-covered electric device.   The film-covered electrical device case according to claim 4, wherein a portion of the holding material that contacts the electrode is corrugated.   The film-covered electrical device case according to claim 4, wherein a portion of the holding material that contacts the electrode has a convex shape.   The film-covered electrical device case according to any one of claims 1 to 6, wherein the holding material is an ultraviolet curable resin.   The frame member is provided with an exhaust gas passage for guiding the gas generated inside the film-covered electrical device to the outside so as to divide the opening into two. The film-covered electrical device case according to claim 1. A method for producing a film-covered electrical device case for storing a film-covered electrical device having a chargeable / dischargeable electrical device element and an exterior film covering the electrical device element,
A frame member forming step of forming a pair of frame members having openings in regions corresponding to the electrical device elements;
The frame member forming step includes a holding material forming step of forming a pair of holding materials having opposite shapes on the mutually facing surfaces of the pair of frame members.
A method for producing a case for a film-covered electrical device.

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