JP4666131B2 - LAMINATE FILM HEAT FUSION METHOD, FILM PACKAGE BATTERY MANUFACTURING METHOD, AND LAMINATE FILM HEAT FUSION DEVICE - Google Patents

Description

  The present invention relates to a method for manufacturing a film-clad battery in which a battery element is hermetically sealed (hereinafter simply referred to as confidential sealing) with an exterior material made of a laminate film, and in particular, a lead terminal is extended when the battery element is sealed. The present invention relates to a method for heat-sealing a laminate film at a side to be processed. The present invention also relates to a heat sealing apparatus for a laminate film for heat-sealing a laminate film for a film-clad battery.

  In recent years, batteries as power sources for portable devices and the like are strongly required to be light and thin. Therefore, it is possible to further reduce the weight and thickness of the battery packaging material, and as a packaging material that can take any shape, a metal thin film or a metal thin film and a heat-sealable resin film are laminated. The one using the laminated film is used.

  A typical example of a laminate film used as a battery exterior material is to laminate a heat-sealable resin film as a heat seal layer on one side of an aluminum thin film as a metal thin film and a protective film on the other side. Three-layer laminated film.

  In a film-clad battery using a laminate film as a packaging material, generally, as shown in FIG. 5, a battery element 106 composed of a positive electrode, a negative electrode, an electrolyte, and the like is placed with a heat-fusible resin film facing each other. The battery element 106 is sealed by heat-sealing the laminate film 103, 104 around the battery element 106 (the area shown by hatching in the figure) between the two laminate films 103, 104. .

  In order to draw out the positive electrode and the negative electrode of the battery element 106 to the outside of the laminate films 103 and 104, the positive electrode and the negative electrode are each provided with an uncoated portion made of a metal foil to which no electrode material is applied. Lead terminals 105a and 105b are extended from the laminate films 103 and 104 and connected to current collectors 107a and 107b in which the coating portions are grouped for each pole. Further, at least one of the laminate films 103 and 104 is formed into a hooked container shape by deep drawing so that the battery element 106 can be easily stored.

  Here, as shown in FIG. 6, the laminate film is heat-sealed by heating the laminate films 103 and 104 while pressing them with a pair of heat-fusing heads 109a and 109b. At this time, the heat given by the heat fusion heads 109a and 109b is also transmitted to the periphery of the portions of the laminate films 103 and 104 where the heat fusion is to be performed. 104d may melt. When the heat-sealable resins 103d and 104d melt at the portions A and B that are in contact with the battery element 106, the battery element 106 comes into contact with the metal thin films 103e and 104e of the laminate films 103 and 104, and a short circuit occurs between them. There is a risk of it.

  Therefore, in Patent Document 1, a heat-fusible resin film made of the same material as that of the heat-fusible resin is disposed at and near the portion to be heat-sealed of the laminate film, so that it is substantially at the place where a short circuit can occur. In particular, a battery is disclosed in which a short circuit is prevented by increasing the thickness of the heat-fusible resin layer.

In Patent Document 2, as a technique for improving the heat resistance of a laminate film, an electronic element is sealed with a laminate film, and then heat fusion is performed by irradiating an electron beam to a heat-sealed region of the laminate film. It is disclosed that a cross-linked structure is formed in a functional resin to improve sealing reliability.
JP 2001-126678 A JP 2001-6633 A

  However, in the one disclosed in Patent Document 1, the thickness of the heat-fusible resin layer is merely partially increased, and when sealing the battery element, in the vicinity of the portion to be heat-sealed, There is no change in that the heat-fusible resin melts even in a region where a short circuit can occur. Therefore, if the heat fusion conditions are not set appropriately according to the thickness of the layer of the heat-fusible resin, the heat-fusing resin is not sufficiently performed, or conversely, the heat-fusing resin is melted too much. There is a risk of short circuit with the metal thin film.

  In particular, the side where the lead terminal extends has a region where the laminate films are directly heat-sealed, and a region where the lead terminal is interposed between the laminate films. The thickness is different. Therefore, conventionally, in order to make the heat fusion conditions uniform in each region, a laminate film is used by using a heat fusion head in which a recess is formed at a position corresponding to the lead-out portion where the lead terminal is interposed. The pressure is applied with a uniform force.

  However, in the lead terminal lead-out part, the heat given from the heat fusion head is easily transmitted through the lead terminal, and the laminate film is not easily heated, so the temperature is higher than the side where the lead terminal is not interposed. It is necessary to heat-seal. Therefore, although the heat fusion of the side where the lead terminal is interposed is appropriately heat-sealed in the region where the lead terminal is interposed, the laminate film is excessively heated in the region where the lead terminal is not interposed. Therefore, the heat-fusible resin is also melted more than necessary, and as a result, there is a possibility that a short circuit occurs in the portions A and B shown in FIG.

  On the other hand, what is disclosed in Patent Document 2 improves the heat resistance itself of the heat-fusible resin of the laminate film, but improves the sealing reliability at the heat-sealed portion after heat-sealing. It does not prevent a short circuit between the battery element and the metal thin film that occurs during sealing.

  In the present invention, when a battery element is sealed with a laminate film of a heat-fusible resin layer and a metal thin film layer, contact with the battery element is particularly caused by heat given at the time of heat-sealing on the side where the lead terminal extends. An object is to prevent a short circuit between the battery element and the metal thin film due to melting of the heat-fusible resin at the portion.

In order to achieve the above object, the method for heat-sealing a laminate film of the present invention uses a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated, and the lead terminals of the positive electrode and the negative electrode are connected. A method for heat-sealing a laminate film on a side where a lead terminal extends when a battery element is sealed by extending the lead terminal from at least one side of the laminate film, wherein the laminate film is pressurized and head body for heating, and the laminate film pressurizing face of the head main body, a lower thermal conductivity than the head main body attached only to at least a portion of the realm to be opposed to only the laminated film at the time of heat-sealing A process for preparing a heat fusion head having a member made of a material, and a battery element with a laminate film with a heat fusion resin layer inside. And the step of surrounding the heat-fusible resin layers with each other at the peripheral edge of the laminate film, and the peripheral edge of the laminate film at the side where the lead terminal extends. And a step of heating while pressurizing with a heat-fusing head.

When the side where the lead terminal of the laminate film extends is heat-sealed, there are a region where the lead terminal is interposed between the laminate films and a region only of the laminate film. Compared with the region where the lead terminal is interposed, the region having only the laminate film is likely to melt the heat-fusible resin layer when pressed and heated by the heat-fusion head. Therefore, the thermal fusion head is configured to include a head body and a member made of a material having a lower thermal conductivity than the head body, and a member made of a material having a lower thermal conductivity than the head body is added to the laminate film of the head body. the pressure surface, by attaching only at least a portion of the realm to be opposed only laminated film during thermal fusion, melting of the heat-fusible resin layer in a region facing only laminated film is relaxed. Thereby, the heat-fusible resin layer is not excessively melted, and a short circuit between the battery element and the metal thin film layer is prevented.

  The method for producing a film-clad battery of the present invention includes a battery element to which positive and negative lead terminals are connected, a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated. A method for producing a film-clad battery sealed in a state extending from at least one side of the battery, comprising a step of producing a battery element, and a step of sealing the battery element with a laminate film. The step of sealing includes heat-welding the side where the lead terminal of the laminate film extends by the method for heat-sealing the laminate film of the present invention.

  In the film-clad battery manufacturing method of the present invention, the above-described method of heat-sealing a laminate film of the present invention is applied to the heat-bonding of the laminate film on the side where the lead terminals extend. Thereby, the short circuit between the battery element and the metal thin film layer at the contact portion between the battery element and the laminate film at the time of heat-sealing the laminate film is prevented, and the reliability of the film-covered battery is improved.

In the heat fusion apparatus for laminate film of the present invention, the battery element to which the positive and negative lead terminals are connected is a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated. A heat-sealing device for a laminated film for heat-welding a side of a laminated film film in which a lead terminal of a laminated film is extended, wherein the laminated film is sealed from at least one side. The heat fusion head includes a head main body for pressurizing and heating the laminate film and a surface of the head main body on which the laminate film is pressed. material having a lower thermal conductivity than the head main body attached only to at least a portion of the realm to be opposed to only the laminated film at the time of wear And having a Ranaru member.

  According to the present invention, it is possible to prevent excessive melting of the heat-fusible resin layer of the laminate film at the time of heat-sealing at the side where the lead terminal of the laminate film extends. As a result, a short circuit between the battery element and the metal thin film due to melting of the heat-fusible resin layer at the contact portion between the battery element and the laminate film can be effectively prevented, and a highly reliable film-clad battery is manufactured. be able to.

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

  FIG. 1 is an exploded perspective view of a film-clad battery according to an embodiment of the present invention. The film-clad battery 1 of the present embodiment includes a battery element 6, a positive electrode current collector 7a and a negative electrode current collector 7b provided in the battery element 6, an outer package that houses the battery element 6 together with an electrolyte, and a positive electrode current collector. It has a positive electrode lead terminal 5a connected to the electric part 7a and a negative electrode lead terminal 5b connected to the negative electrode current collector 7b.

  The battery element 6 is configured by alternately laminating a plurality of positive plates and a plurality of negative plates each coated with an electrode material on both sides via a separator. From one side of each positive electrode plate and each negative electrode plate, an uncoated portion made of a metal foil to which no electrode material is applied is provided so as to protrude between the uncoated portions of the positive electrode plate and between the uncoated portions of the negative electrode plate Are collectively ultrasonically welded to form the positive electrode current collector 7a and the negative electrode current collector 7b.

  In the case of a nonaqueous electrolyte battery such as a lithium ion battery, an aluminum plate is used as the positive electrode lead terminal 5a, and a nickel plate or a copper plate is used as the negative electrode lead terminal 5b. The copper plate constituting the negative electrode lead terminal 5b may be plated with nickel.

  The resin film 8 is preliminarily heat-sealed to the positive electrode lead terminal 5a and the negative electrode lead terminal 5b in order to prevent a decrease in heat-fusibility due to the presence of a metal plate when the laminate films 3 and 4 are heat-sealed. Has been. The resin film 8 is heat-sealed from both surfaces of the positive electrode lead terminal 5a and the negative electrode lead terminal 5b in at least a region between the positive electrode lead terminal 5a and the negative electrode lead terminal 5b sandwiched between the laminate films 3 and 4.

  The exterior body is composed of two laminated films 3 and 4 that sandwich and surround the battery element 6 from above and below, and the battery element 6 is sealed by heat-sealing the peripheral portions of the laminated films 3 and 4. . In FIG. 1, regions where the laminate films 3 and 4 are heat-sealed are indicated by hatching as sealing regions 3 a and 4 a.

  One laminate film 3 is processed into a hooked container shape so that a recess is formed when viewed from the battery element 6 side in order to form a chamber for housing the battery element 6. This recess can be formed by, for example, deep drawing. In the example shown in FIG. 1, the concave portion is formed in one laminate film 3, but it may be formed in the other laminate film 4. Depending on the thickness of the battery element 6, a concave portion may be formed in both the laminate films 3 and 4, or the battery element 6 may be sealed using the flexibility of the laminate films 3 and 4 without forming the concave portion. You may stop.

  As the laminate films 3 and 4, a film generally used for this type of film-clad battery can be used as long as the battery element 6 can be sealed so that the electrolyte does not leak. In FIG. 2, sectional drawing in the sealing area vicinity of the film-clad battery 1 is shown.

  As shown in FIG. 2, the laminate films 3 and 4 each have a structure in which at least metal thin film layers 3e and 4e and heat-fusible resin layers 3d and 4d are laminated. In the present embodiment, protective layers 3f and 4f made of a film of polyester such as polyethylene terephthalate or nylon are laminated on the surface of the metal thin film layers 3e and 4e opposite to the heat-fusible resin layers 3d and 4d. However, the protective layers 3f and 4f are provided as necessary.

  As the metal thin film layers 3e and 4e, for example, a foil of Al, Ti, Ti-based alloy, Fe, stainless steel, Mg-based alloy having a thickness of 10 μm to 100 μm can be used. The resin used for the heat-sealable resin layers 3d and 4d is not particularly limited as long as it is a resin that can be heat-sealable, and examples thereof include polypropylene, polyethylene, acid modified products thereof, polyphenylene sulfide, and polyethylene terephthalate. Polyester, polyamide, ethylene-vinyl acetate copolymer and the like can be used.

  The film-clad battery 1 configured as described above is manufactured as follows.

  First, a battery element 6 in which a plurality of positive electrode plates and a plurality of negative electrode plates are alternately laminated via separators and further formed with a positive electrode current collector 7a and a negative electrode current collector 7b is produced. To be precise, the laminate made of the positive electrode plate, the separator, and the negative electrode plate obtained at this stage is also called a battery element precursor in the stage before impregnating the electrolytic solution. It is simply expressed as battery element 6.

  Next, the positive electrode lead terminal 5a is connected to the positive electrode current collector 7a, and the negative electrode current collector 5b is connected to the negative electrode current collector 7b. The positive electrode current collector 7a is connected to the positive electrode lead terminal 5a and the negative electrode current collector 7b is connected to the negative electrode current collector 7b to form the positive electrode current collector 7a and the negative electrode current collector 7b in order to simplify the manufacturing process. Although it may be performed simultaneously, it may be performed in a separate process.

  Next, the two laminated films 3 and 4 are faced to each other so that the heat-fusible resin layers 3d and 4d are inside, and the battery element 6 to which the positive electrode lead terminal a and the negative electrode lead terminal 5b are connected is sandwiched. Siege. At this time, the positive electrode lead terminal 5a and the negative electrode lead terminal 5b are extended from one side of the laminate films 3 and 4 with the battery element 6 interposed therebetween. Thereby, in the peripheral part (sealing area | region 3a, 4a) of the laminate films 3 and 4, the heat-fusible resin layers 3d and 4d face each other directly. Then, the film-clad battery 1 is manufactured by heat-sealing the laminate films 3 and 4 in the sealing regions 3a and 4a and sealing the battery element 6.

  At the time of sealing, the three sides of the laminate films 3 and 4 are first heat-sealed to form a bag shape in which one side is opened, and the remaining 1 of the laminate films 3 and 4 in the bag shape is opened. The electrolyte is injected from the side, and then the remaining one side is heat-sealed. By injecting the electrolytic solution, the electrolytic solution penetrates into the battery element 6. The three sides of the heat fusion performed before the injection of the electrolyte may be performed collectively for the three sides, or may be performed in a plurality of steps (for example, one side at a time). In addition, the battery element 6 can be impregnated with an electrolytic solution prior to the thermal fusion of the laminate films 3 and 4, and then the four sides can be thermally fused together.

  Here, thermal fusion of the laminate films 3 and 4 at the sides where the positive electrode lead terminal 5a and the negative electrode lead terminal 5b extend will be described in more detail with reference to FIG. FIG. 3 is a cross-sectional view along the side where the lead terminal is interposed in the sealing region at the time of heat-sealing the side where the lead terminal of the film-clad battery shown in FIG. 1 is interposed.

  The laminating films 3 and 4 are heat-sealed by heating while pressing the laminating films 3 and 4 between the pair of heat-sealing heads 11 and 12. The pressing surface, which is the surface for pressing the laminate films 3 and 4 of the heat-fusing heads 11 and 12, is a portion where the positive electrode lead terminal 5a, the negative electrode lead terminal 5b and the resin film 8 are interposed between the laminate films 3 and 4. And unevenness corresponding to the unevenness of the surfaces of the laminate films 3 and 4 due to the presence of portions where these are not interposed. Thus, the laminate films 3 and 4 are pressed with a substantially uniform force at the time of heat sealing.

  The heat fusion heads 11 and 12 have head main bodies 11a and 12a and heat insulating materials 11b and 12b. The head main bodies 11a and 12a incorporate a heater (not shown) and have a flat pressing surface. The heat insulating materials 11b and 12b constitute the convex portions of the heat fusion heads 11 and 12, and the positive electrode lead terminal 5a, the negative electrode lead terminal 5b and the resin at the time of heat fusion of the pressure surfaces of the head main bodies 11a and 12a. In a region facing only the laminate films 3 and 4 where none of the films 8 is interposed, the film 8 is attached as a convex structure portion with respect to the pressure surfaces of the head main bodies 11a and 12a.

  The heat insulating materials 11b and 12b are plate-like members and are made of a material having a lower thermal conductivity than the head main bodies 11a and 12a. As the heat insulating materials 11b and 12b, ceramic, heat resistant resin, or the like can be used. Further, when the head main bodies 11a and 12a are made of aluminum, iron or stainless steel can be used as the heat insulating materials 11b and 12b.

  In the heat fusion of the side where the positive electrode lead terminal 5a and the negative electrode lead terminal 5b are interposed, the heat fusion is performed at a temperature higher than the temperature at the time of heat fusion of the other side. For this reason, in the region where the laminate films 3 and 4 sandwich the positive electrode lead terminal 5a or the negative electrode lead terminal 5b, heat from the head main bodies 11a and 12a is transmitted through the positive electrode lead terminal 5a and the negative electrode lead terminal 5b, and further, the resin film. Even in the situation where the thickness of the resin layer to be melted is increased due to the presence of 8, the laminate films 3 and 4 are heated to a temperature suitable for thermal fusion with the resin film 8. As a result, the heat-fusible resin layers 3d and 4d and the resin film 8 of the laminate films 3 and 4 are melted to the extent necessary for the heat-sealing of both.

  On the other hand, in the region where the positive electrode lead terminal 5a or the negative electrode lead terminal 5b does not exist between the laminate films 3 and 4, there is no factor that makes the resin difficult to melt as described above, so the heat applied from the head bodies 11a and 12a. Becomes excessive for the laminated films 3 and 4. However, in this region, the heat insulating materials 11b and 12b exist between the head main bodies 11a and 12a and the laminate films 3 and 4, and compared with the region where the positive electrode lead terminal 5a or the negative electrode lead terminal 5b is interposed, The temperature of the laminate films 3 and 4 is lowered. As a result, in this region, the laminate films 3 and 4 are heated to a temperature suitable for heat fusion, and the laminate films 3 and 4 are heated to the extent necessary for heat fusion between the laminate films 3 and 4. Melted.

  As described above, a part of the thermal fusion heads 11 and 12 is made of a material having a lower thermal conductivity than the other part, and a necessary and sufficient amount of heat is obtained depending on the layer structure of the thermal fusion part. , 4, the heat-fusible resin layers 3 d, 4 d are not excessively heated in all the regions heated by the heat-fusing heads 11, 12. Therefore, the heat-fusible resin layers 3d and 4d are not melted more than necessary while reliably performing the heat-sealing at the portion where the positive electrode lead terminal 5a and the negative electrode lead terminal 5b are interposed. As a result, the battery element 6 Thus, short circuit between the battery element 6 and the metal thin film layers 3e and 4e at the contact portion between the laminated film 3 and the laminated film 3 and 4 can be prevented, and the highly reliable film-clad battery 1 can be manufactured.

  FIG. 4 shows a cross-sectional view along the side where the lead terminal is interposed in the sealing region at the time of heat-sealing the side where the lead terminal is interposed, according to another embodiment of the present invention. In FIG. 4, since the film-clad battery is configured in the same manner as in the above-described embodiment, the same components as those in FIG.

  In the heat fusion heads 21 and 22 shown in FIG. 4, regions where the pressure surfaces themselves of the head main bodies 21a and 22a face only the laminate films 3 and 4 at the time of heat fusion are formed as convex portions. And a part of this convex part is substituted by the heat insulating materials 21b and 22b. In other words, the convex portions of the head main bodies 21a and 22a are formed with concave portions, and the heat insulating materials 21b and 22b are held by the head main bodies 21a and 22a in a state of being embedded in the concave portions and exposing the surfaces. The convex portions of the heat fusion heads 21 and 22 pressurize and heat the area where only the laminate films 3 and 4 exist, but some of the head main bodies 21a and 22a are not heat insulating plates 21b and 22b. Laminate films 3 and 4 are heated under pressure.

  For example, at the boundary between the part where the laminate films 3 and 4 directly face each other and the part where the other member (resin film 8) is interposed between the laminate films 3 and 4, the laminate films 3 and 4. If the film is not sufficiently heated and melted, a gap is formed between the laminate films 3 and 4, and the airtightness inside and outside the film-covered battery may be impaired. Further, when the interval between the positive electrode lead terminal 5a and the negative electrode lead terminal 5b is large and the area of the portion where the laminate films 3 and 4 are directly opposed to each other is large, the heat melting only by the heat insulating plates 21b and 22b. The adhesive resin layers 3d and 4d may not be sufficiently melted.

  Therefore, the ratio of the surface area of the heat insulating plates 21b and 22b to the surface area of the pressing surface of the convex portions can be appropriately set by embedding the heat insulating plates 21b and 22b in the convex portions of the heat fusion heads 21 and 22. . As a result, compared with the heat fusion heads 11 and 12 shown in FIG. 3, more heat is transmitted from the convex portions to the laminate films 3 and 4, and even in the case described above, the laminate films 3 and 4 are directly opposed to each other. The part to be heat-sealed can be surely heat-sealed.

  The ratio of the surface area of the heat insulating plates 21b and 22b to the surface area of the pressing surface of the convex part, and the position (distribution) of the heat insulating plates 21b and 22b on the pressing surface of the convex part depend on the structure or material of the object to be heat-sealed. It can be set arbitrarily depending on the situation. In the thermal fusion heads 21 and 22 shown in FIG. 4, at the boundary between the part where the laminate films 3 and 4 directly face each other and the part where the resin film 8 is interposed between the laminate films 3 and 4. In order to melt the heat-fusible resin layers 3d and 4d satisfactorily, the heat insulating plates 21b and 22b are arranged so that the head main bodies 21a and 22a press the laminate films 3 and 4 at the side portions of the convex portions. .

  Further, the thermal insulation plates 21b and 22b are embedded and held in the head main bodies 21a and 22a, so that the displacement of the thermal insulation plates 21b and 22b can be prevented.

  The present invention has been described above with some typical examples. However, the present invention is not limited to these examples, and it is obvious that the present invention can be appropriately modified within the scope of the technical idea of the present invention. .

  For example, in the above-mentioned example, the battery element is sandwiched from both sides in the thickness direction by two laminated films and the surrounding four sides are heat-sealed. In addition, one laminated film is folded in two. The battery element may be sealed by sandwiching the battery element and thermally fusing the three open sides.

  Moreover, as a battery element, if the positive electrode, the negative electrode, and electrolyte are included, the arbitrary battery elements used for a normal battery are applicable. Battery 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 / undoped 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. In addition, the present invention is applicable to battery elements of other types of chemical batteries such as nickel metal hydride batteries, nickel cadmium batteries, lithium metal primary batteries or secondary batteries, lithium polymer batteries, and capacitor elements. is there.

  Regarding the structure of the battery element, in the above-described example, a laminated type in which a plurality of positive plates and negative plates are alternately laminated was shown. However, the positive plate, the negative plate, and the separator are formed in a strip shape, and the positive plate and A wound battery element in which the positive electrode and the negative electrode are alternately arranged by stacking the negative electrode plates, winding them, and then compressing them in a flat shape may be used.

  Further, in the above-described example, the resin film 8 is preliminarily welded to the positive electrode lead terminal 5a and the negative electrode lead terminal 5b. However, the heat-fusible resin layers 3d and 4d are made of a material having excellent adhesion to metal. In this case, the positive electrode lead terminal 5a and the negative electrode lead terminal 5b may be directly sandwiched between the laminate films 3 and 4 without using the resin film 8, and the present invention is applicable even in this case. Moreover, although the example which applied this invention to the film-clad battery 1 which extended the positive electrode lead terminal 5a and the negative electrode lead terminal 5b from the same edge | side of the film-clad battery 1 was shown, these lead terminals are respectively different sides, for example, mutually The present invention can also be applied to a film-clad battery extended from opposite sides.

It is a disassembled perspective view of the film-clad battery by one Embodiment of this invention. It is sectional drawing in the sealing region vicinity of the film-clad battery shown in FIG. It is sectional drawing along the edge | side where the lead terminal in a sealing area | region at the time of the heat sealing | fusion of the edge | side where the lead terminal of the film-clad battery shown in FIG. It is sectional drawing along the edge | side where the lead terminal in a sealing area | region at the time of the heat sealing | fusion of the edge | side where a lead terminal interposes by other embodiment of this invention. It is a disassembled perspective view of the conventional film-clad battery. It is sectional drawing in the sealing region vicinity of the laminate film at the time of the heat sealing | fusion in the film-clad battery shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film-clad battery 3, 4 Laminate film 3a, 4a Sealing area 3d, 4d Heat-fusion resin layer 3e, 4e Metal thin film layer 3f, 4f Protective layer 5a Positive electrode lead terminal 5b Negative electrode lead terminal 6 Battery element 7a Positive electrode current collection Part 7b Negative electrode current collector part 11, 12, 21, 22 Heat fusion head 11a, 12a, 21a, 22a Head body 11b, 12b, 21b, 22b

Claims (7)

Using a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated, a battery element having positive and negative lead terminals connected thereto is extended from at least one side of the laminate film. A method of heat-sealing the laminate film on the side where the lead terminal extends,
Head body for pressurizing and heating the laminate film, and the laminate film pressed surface of the head main body, attached only to at least a portion of the realm of the facing only laminated film during thermal fusion Preparing a heat fusion head having a member made of a material having a lower thermal conductivity than the head body;
The battery element is surrounded by the laminate film with the lead terminals extending from at least one side with the heat-fusible resin layer inside, and the heat-fusible resin layer at the periphery of the laminate film The process of facing each other,
And a step of heating the peripheral edge of the laminate film at the side where the lead terminal extends, while applying pressure with the heat fusion head. The battery element to which the positive and negative lead terminals are connected is a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated, and the lead terminal is extended from at least one side of the laminate film. A method for producing a film-clad battery sealed in a state,
Producing the battery element;
Sealing the battery element with the laminate film,
The step of sealing the battery element is a method for manufacturing a film-clad battery, which includes thermally welding the side of the laminate film where the lead terminals extend by the heat fusion method according to claim 1 . The method for manufacturing a film-clad battery according to claim 2 , wherein the battery element is a chemical battery element or a capacitor element. The battery element to which the positive and negative lead terminals are connected is a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated, and the lead terminal extends from at least one side of the laminate film. A heat-sealing device for a laminate film for heat-welding the side of the laminate film where the lead terminals of the film-coated battery are sealed,
A pair of heat fusion heads for heating the laminate film while applying pressure;
The heat-fusible head comprises a head main body for pressing and heating the laminated film, the laminated film pressurizing surface of the head body, at least the realm opposed only to the laminate film at heat sealing And a member made of a material having a lower thermal conductivity than that of the head main body, which is attached only to a part thereof. The pressing surface for pressing the laminate film of the head body is a flat surface, and the member made of a material having a lower thermal conductivity than the head body is the laminate film at the time of thermal fusion of the pressing surface of the head body. The heat sealing apparatus for laminate films according to claim 4 , wherein the apparatus is attached as a convex structure portion with respect to the pressure surface only in a region facing only the film. The pressure surface for pressing the laminate film of the head main body is formed as a convex portion in a region facing only the laminate film at the time of heat fusion, and a part of the convex portion has a thermal conductivity higher than that of the head main body. The heat sealing apparatus for laminate film according to claim 4 or 5 , wherein the heat sealing apparatus is replaced with a member made of a low-quality material . The heat sealing apparatus for laminate film according to claim 6 , wherein the member made of a material having a lower thermal conductivity than the head body is embedded with the surface exposed to the convex portion of the head body.

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