JP4636223B2 - 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 producing 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, heat fusion of a laminate film when sealing the battery element Regarding the method. 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. 6, 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 connected to current collectors 107a and 107b in which the coating portions are grouped for each pole so as to protrude from the laminate films 103 and 104. 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. 7, the heat fusion of the laminate film is performed by heating the laminate films 103 and 104 while applying pressure to the pair of heat fusion 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.

On the other hand, 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 addition, when using a deep-drawn laminate film to form a region in which battery elements are stored, the portion of the laminate film that contacts the battery element is the portion where the laminate film is deep-drawn. There are many. Therefore, even if a heat-sealable resin film for preventing short-circuiting is provided, the thickness of the heat-sealable resin layer is reduced by deep drawing and the effect as expected cannot be obtained. .

  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, the heat-fusible resin melts at the contact portion with the battery element by heat applied during heat-sealing. An object is to prevent short circuit between the battery element and the metal thin film.

In order to achieve the above-mentioned 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. A method for heat-sealing a laminate film when stopping,
Surrounding the battery element with a laminate film with the heat-fusible resin layer inside, and facing the heat-fusible resin layers with each other at the periphery of the laminate film, and the periphery of the laminate film surrounding the battery element A step of heating while pressing with a pair of heat fusion heads, and the step of heating is at least an edge portion of the battery element in the heat fusion head side in the region in contact with the battery element of the laminate film contact area which is, so as not to a temperature above the melting point of the thermally adhesive resin layer and, viewed including the step of inhibiting the temperature rise of the laminate film, the step of suppressing the temperature increase of the laminate film, a laminate film and characterized in including Mukoto to the thickness direction from one side or both sides of the injection air toward the laminated film.

Further, heat how to wear method of the laminate film of the present invention uses a laminate film of at least heat-fusible resin layer and the metal thin film layer are laminated, the time of sealing surrounding the battery element with the laminate film A method of heat-sealing a laminate film,
Surrounding the battery element with the laminate film with the heat-fusible resin layer on the inside, and facing the heat-fusible resin layers at the periphery of the laminate film, and the periphery of the laminate film surrounding the battery element A step of heating while pressing with a pair of heat fusion heads, and the step of heating is at least an edge portion on the heat fusion head side of the battery element in the region of the laminate film in contact with the battery element Including a step of suppressing a rise in the temperature of the laminate film so that the region in contact with the temperature does not exceed the melting point of the heat-fusible resin layer. At least one battery element side surface of the fusion head is brought into contact with the laminate film when the laminate film is pressed by the thermal fusion head. , As a gap between the side surface occurs, characterized in that it comprises attaching a heat insulating plate.

In the method for heat-sealing a laminate film of the present invention, when the laminate film is heated by a heat-fusing head, the temperature rise of the laminate film is suppressed in a region where a short circuit is most likely to occur. Thereby, melting | fusing of the heat-fusible resin layer in the area | region which is contacting the edge part of a battery element of a laminate film is prevented, and the short circuit with a battery element and a metal thin film layer is prevented .

  The method for producing a film-clad battery of the present invention is a method for producing a film-clad battery in which a battery element is sealed with a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated. And a step of sealing the battery element by the heat sealing method of the laminate film of the present invention.

The heat sealing apparatus for laminate film of the present invention is a heat sealing apparatus for laminate film for sealing a battery element with a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated. A pair of heat fusion heads for heating the laminate film while pressurizing, and at least an edge portion of the battery element in contact with the battery element of the laminate film in contact with the heat fusion head side. region, so as not to a temperature above the melting point of the heat-fusible resin layer, have a and suppressing temperature rise suppression means an increase in the temperature of the laminate film, the temperature rise suppression means, injects air toward the laminated film Oh Ru in the air nozzle to be.
Further, the heat fusion device for laminate film of the present invention is a heat fusion device for laminate film for sealing a battery element with a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated. A pair of heat fusion heads for heating the laminate film while applying pressure, and at least an edge portion of the laminate film in contact with the battery element at the edge of the battery element on the heat fusion head side. Temperature rise suppression means for suppressing the temperature rise of the laminate film so that the region where the temperature is not higher than the melting point of the heat-fusible resin layer, and the temperature rise suppression means is a pair of heat fusion heads The side surface of the battery element is attached to the side surface of at least one of the battery elements so as to come into contact with the laminate film when the laminate film is pressed by the heat-fusing head. A heat insulating plate which is mounted so that a gap is formed between the.

In laminated film for heat sealing apparatus of the present invention, the cross-sectional heat plate is desirably composed of low thermal conductivity material than thermal fusion head.

  According to the present invention, it is possible to effectively prevent a short circuit between the battery element and the metal thin film due to melting of the heat-fusible resin layer at the edge portion of the battery element at the time of heat-sealing the laminate film, and reliability. High film-clad battery can be manufactured.

  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.

  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. 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 electrolytic solution may be performed collectively for the three sides or may be performed in a plurality of steps. 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, the heat fusion of the laminate films 3 and 4 will be described in more detail with reference to FIG. FIG. 3 is a cross-sectional view of the film-clad battery shown in FIG. 1 in the vicinity of the sealing region when the laminated film is heat-sealed.

  The heat sealing of the laminate films 3 and 4 in the sealing regions 3a and 4a is performed by heating while pressing the laminate films 3 and 4 between the pair of heat fusion heads 9a and 9b. Air nozzles 8a and 8b for injecting air toward the laminate films 3 and 4 are arranged in the vicinity of the heat fusion heads 9a and 9b, respectively. In particular, the air nozzles 8a and 8b inject air toward the region of the laminate films 3 and 4 in which the battery element 6 is stored.

  When the laminating films 3 and 4 are heat-sealed, the laminating films 3 and 4 are melted in the region where the heat-fusing heads 9a and 9b are pressed, and the laminating films 3 and 4 are melted. 4 fuse together. At this time, since air is jetted from the air nozzles 8a and 8b, in the area where the air is jetted, the heat transmitted from the heat-fusing heads 9a and 9b is forcibly radiated from the laminate films 3 and 4, Temperature rise is suppressed. Further, by ejecting air from the air nozzles 8a and 8b, radiation of heat from the heat fusion heads 9a and 9b to the battery element 6 side is also suppressed. Air is jetted from the air nozzles 8a and 8b so that the temperature of the heat-fusible resin layers 3d and 4d does not exceed the melting point, and as a result, the heat-fusible resin layers 3d and 4d are melted at the time of heat-fusing. Is prevented.

  As described above, air is jetted from the air nozzles 8a and 8b when the laminated films 3 and 4 are heat-sealed, thereby preventing the heat-fusible resin layers 3d and 4d from melting other than the sealing regions 3a and 4a. In the laminate films 3 and 4, the metal thin film layers 3 e and 4 e are not exposed even at the contact portion with the battery element 6, and a short circuit between the metal thin film layers 3 e and 4 e and the battery element 6 can be prevented. Therefore, as in the prior art, the thickness of the heat-fusible resin layers 3d and 4d is increased more than necessary, or a process for improving the heat resistance of the heat-fusible resin layers 3d and 4d is added. Without short-circuiting, the metal thin film layers 3e, 4e and the battery element 6 can be prevented from being short-circuited.

  In order to more effectively suppress the temperature rise of the laminate films 3 and 4 due to the air injection, the air nozzles 8a and 8b are brought into contact with the heat fusion heads 9a and 9b and the battery element 6 of the laminate films 3 and 4, respectively. It is preferable to arrange so as to inject air into a region between the parts to be performed. By disposing the air nozzles 8a and 8b in this way, the heat transferred from the heat fusion heads 9a and 9b to the laminate films 3 and 4 can be dissipated before reaching the portion in contact with the battery element 6.

  It is not necessary for the air nozzles 8a and 8b to eject the air to the entire region where the laminate films 3 and 4 are in contact with the battery element 6. A short circuit may occur in a region in contact with the edge portion of the battery element 6 among the regions in contact with the battery element 6 of the laminate films 3 and 4. Among these, it is a region on the side of the heat fusion heads 9a and 9b that the heat-fusible resin layers 3d and 4d are easily melted at a high temperature. Therefore, the region of the laminate films 3 and 4 that is in contact with at least the edge portion of the battery element 6 on the side of the heat fusion heads 9a and 9b does not have a temperature higher than the melting point of the heat fusion resin layers 3d and 4d. If air can be injected, air may be partially injected to the laminate films 3 and 4. From the viewpoint of cooling the laminate films 3 and 4, the temperature of air sprayed from the air nozzles 8 a and 8 b is preferably as low as possible without affecting the functions of the laminate films 3 and 4 and the battery element 6. The air at room temperature is sufficient.

  FIG. 3 shows an example in which the air nozzles 8a and 8b are provided corresponding to the upper and lower heat fusion heads 9a and 9b, respectively. However, air is injected from only one side in the thickness direction of the laminate films 3 and 4. Thus, if the temperature rise of the heat-fusible resin layers 3d and 4d in the region in contact with the edge portion of the battery element 6 on the heat-fusing head 9a and 9b side can be suppressed, either one of the heat-fusing components The air nozzles may be provided only on the landing heads 9a and 9b, and the air may be ejected from only one side.

  FIG. 4 is a cross-sectional view in the vicinity of the sealing region when the laminate film is heat-sealed according to another embodiment of the present invention. Since the film-clad battery is configured similarly to that shown in FIG. 1, in FIG. 4, the same reference numerals as those shown in FIG.

  In the example shown in FIG. 4, heat insulating plates 18 a and 18 b made of a material having a lower thermal conductivity than the thermal fusion heads 19 a and 19 b are attached to the side surfaces of the thermal fusion heads 19 a and 19 b on the battery element 6 side. The heat insulating plates 18a and 18b are also configured to come into contact with the laminate films 3 and 4 when the laminate films 3 and 4 are pressed by the heat fusion heads 19a and 19b. As the heat insulating plates 18a and 18b, ceramic, heat resistant resin, or the like can be used. When the heat fusion heads 19a and 19b are made of aluminum, iron or stainless steel can be used as the heat insulating plates 18a and 18b.

  By providing the heat sealing heads 19a and 19b with the heat insulating plates 18a and 18b, heat transmitted to the battery element 6 side through the laminate films 3 and 4 and heat from the heat sealing heads 19a and 19b to the battery element 6 side. It is possible to suppress the temperature rise of the laminate films 3 and 4 outside the region heat-sealed by the heat-sealing heads 19a and 19b due to the radiation of. This prevents melting of the heat-fusible resin layers 3d and 4d at the portions of the laminate films 3 and 4 that are in contact with the battery element 6, and as a result, the battery element 6 and the metal thin film layers 3e and 4e Can be prevented.

  The heat insulating plates 18a and 18b pressurize the laminate films 3 and 4, but the portions are pressed by the heat insulating plates 18a and 18b of the laminate films 3 and 4 by appropriately setting the thickness thereof. Alternatively, the heat-fusible resins 3d and 4d can be melted by heat transfer from the heat-fusing heads 19a and 19b, and heat-sealed.

  In the example shown in FIG. 4, the heat insulating plates 18a and 18b are attached in close contact with the side surfaces of the heat fusion heads 19a and 19b, but the heat insulation plates 18a and 18b formed by the heat fusion heads 19a and 19b are shown. In order to suppress the heating of itself, as shown in FIG. 5, the heat insulating plates 28a, 28b are partially supported by the heat fusion heads 29a, 29b via the support members 30a, 30b, and the heat fusion heads 29a, 29b, You may install away from 29b. The gap between the heat insulating plates 28a and 28b and the heat fusion heads 29a and 29b does not need to be large.

  Further, in this example as well, a heat insulating plate may be provided only on one of the heat fusion heads 29a and 29b as in the case of air injection by an air nozzle.

  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, FIG. 1 shows an example in which the positive electrode lead terminal 5a and the negative electrode lead terminal 5b are extended from the same side of the film-covered battery 1, but these lead terminals extend from different sides, for example, opposite sides. You may let it come out.

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 in the sealing region vicinity at the time of heat sealing | fusion of the film-clad battery shown in FIG. It is sectional drawing in the sealing region vicinity at the time of heat sealing | fusion by other embodiment of this invention. It is sectional drawing in the sealing region vicinity at the time of heat sealing | fusion showing the example of a change of FIG. It is a disassembled perspective view of the conventional film-clad battery. It is sectional drawing in the sealing area 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 exterior battery 3, 4 Laminate film 3a, 4a Sealing area | region 3d, 4d Heat-fusion resin layer 3e, 4e Metal thin film layer 5a Positive electrode lead terminal 5b Negative electrode lead terminal 6 Battery element 7a Positive electrode current collection part 7b Negative electrode current collection Part 8a, 8b Air nozzle 9a, 9b, 19a, 19b, 29a, 29b Thermal fusion head 18a, 18b, 28a, 28b Heat insulation plate 30a, 30b Support member

Claims (9)

Using a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated, a method for heat-sealing the laminate film when enclosing and sealing a battery element with the laminate film,
Surrounding the battery element with the laminate film with the heat-fusible resin layer inside, and facing the heat-fusible resin layers at the periphery of the laminate film; and
Heating the peripheral edge of the laminate film surrounding the battery element while applying pressure with a pair of heat fusion heads,
In the heating step, among the regions of the laminate film that are in contact with the battery element, at least the region of the battery element that is in contact with the edge portion on the heat fusion head side is the heat-fusible resin. so as not to a temperature above the melting point of the layers, viewed including the step of suppressing the temperature rise of the laminated film,
Step of inhibiting an increase in temperature of the laminated film, heat Chakuhoho laminate film characterized in including that to inject air toward the from one or both sides for thickness direction laminate film of the laminated film . Step of inhibiting an increase in temperature of the laminated film, the laminated film comprises injecting air into the region between the heat-fusible head and sites where the battery element is in contact, according to claim 1 Laminate film heat fusion method. Using a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated, a method for heat-sealing the laminate film when enclosing and sealing a battery element with the laminate film,
Surrounding the battery element with the laminate film with the heat-fusible resin layer inside, and facing the heat-fusible resin layers at the periphery of the laminate film; and
Heating the peripheral edge of the laminate film surrounding the battery element while applying pressure with a pair of heat fusion heads,
In the heating step, among the regions of the laminate film that are in contact with the battery element, at least the region of the battery element that is in contact with the edge portion on the heat fusion head side is the heat-fusible resin. Including a step of suppressing the temperature rise of the laminate film so as not to reach a temperature higher than the melting point of the layer,
Step of inhibiting an increase in temperature of the laminate film on at least the side surface of one of the battery element side of the pair of heat-sealing heads, before Symbol laminate film upon pressurization of the laminate film according to the heat-fusible head And attaching a heat insulating plate so that a gap is formed between the side surface and the side surface.
A method for heat-sealing a laminate film, comprising: The method for heat-sealing a laminated film according to claim 3 , wherein the heat insulating plate is made of a material having a lower thermal conductivity than the heat-sealing head. A method for producing a battery case in which a battery element is sealed with a laminate film in which at least a heat-fusible resin layer and a metal thin film layer are laminated,
Producing the battery element;
Method of producing a film-covered battery including a step of sealing the battery element by heat sealing method according to any one of claims 1 to 4. The method for manufacturing a film-clad battery according to claim 5 , wherein the battery element is a chemical battery element or a capacitor element. A laminating film heat sealing apparatus for sealing a battery element with a laminating film in which at least a heat fusible resin layer and a metal thin film layer are laminated,
A pair of heat fusion heads for heating the laminate film while applying pressure;
Of the region of the laminate film that is in contact with the battery element, at least the region that is in contact with the edge portion of the battery element on the heat fusion head side is a temperature equal to or higher than the melting point of the heat-fusible resin layer. so as not to, possess a suppressing temperature rise suppression means the temperature rise of the laminated film,
It said temperature rise suppression means, a laminate film for heat sealing device Ru Ah air nozzle for injecting air toward the laminated film. A laminating film heat sealing apparatus for sealing a battery element with a laminating film in which at least a heat fusible resin layer and a metal thin film layer are laminated,
A pair of heat fusion heads for heating the laminate film while applying pressure;
Of the region of the laminate film that is in contact with the battery element, at least the region that is in contact with the edge portion of the battery element on the heat fusion head side is a temperature equal to or higher than the melting point of the heat-fusible resin layer. In order not to become, it has a temperature rise suppression means for suppressing the temperature rise of the laminate film,
It said temperature rise suppression means, on at least the side surface of one of the battery element side of the pair of heat-sealing heads, that is mounted to contact the laminate film upon pressurization of the laminate film according to the heat-fusible head together, Ru insulating plate der mounted so that a gap occurs between the side surface
La Mi titanate film for heat sealing equipment. The said heat insulation board is a heat sealing apparatus for laminate films of Claim 8 comprised with the material whose heat conductivity is lower than the said heat welding head.

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