JP2001118606A - Lithium secondary battery and sealing device for battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To aim at providing a lithium secondary battery with improved volume energy density. SOLUTION: By heat-sealing each inner surface of the films with the other, in which at least heat-sealing resin is placed at heat-sealing part, the film is made to a cylinder form, which is characterized as having that a sheathing material 3 whose openings 4a, 4b are heat-sealed by said heat-sealing part 5 that is located at upper or lower face, and a generator element that is housed inside of the sheathing material 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lithium secondary battery and a battery sealing device.

[0002]

2. Description of the Related Art In recent years, with the development of electronic equipment, there has been a demand for the development of a non-aqueous electrolyte secondary battery that is small, lightweight, has a high energy density, and can be repeatedly charged and discharged. Such a secondary battery includes a negative electrode using lithium or a lithium alloy as an active material, a positive electrode containing an oxide, sulfide, or selenide such as molybdenum, vanadium, titanium, or niobium as an active material, and a nonaqueous electrolyte. There is known a lithium secondary battery including:

In recent years, a negative electrode containing a carbonaceous material that absorbs and releases lithium ions, such as coke, graphite, carbon fiber, a resin fired body, and pyrolytic gas phase carbon, has been used as a negative electrode. The development and commercialization of lithium ion secondary batteries using lithium and lithium manganese oxide-containing batteries are being actively pursued.

Meanwhile, in order to further reduce the weight and size of the secondary battery, for example, US Pat.
As disclosed in US Patent No. 6,318, a polymer lithium secondary battery has been developed. The polymer lithium secondary battery includes a positive electrode including an active material, a non-aqueous electrolyte, and a polymer holding the electrolyte, a negative electrode including an active material, a non-aqueous electrolyte, and a polymer holding the electrolyte, and the positive and negative electrodes. And a power generation element including a non-aqueous electrolyte and a separator made of an electrolyte sheet containing a polymer holding the electrolyte. This polymer lithium secondary battery is
Since the non-aqueous electrolyte is held by the polymer, it contains substantially no liquid component, and since the positive and negative electrodes and the separator are integrated by the polymer, it is possible to use a thin exterior material such as a laminate film. it can. For this reason, the secondary battery has features of being thin, lightweight, and excellent in safety.

FIG. 11 shows an example of a polymer lithium secondary battery.
Shown in That is, the sheet-like power generating element is configured such that the positive electrode lead 32 and the negative electrode lead 33 electrically connected to the power generating element by the laminate film 31 having the heat-fusible resin disposed on the inner surface thereof extend from the film 31. Is coated. The three open sides of the film 31 are:
Sealed by heat fusion.

[0006]

However, in the above-described polymer lithium secondary battery, since the three sides of the exterior material (laminated film) are heat-sealed areas, the ratio of the power generation element in the battery occupied volume is low. There is a problem that the volume energy density is low.

An object of the present invention is to provide a lithium secondary battery having an improved volume energy density.

Further, the present invention is to improve the volume energy density of a battery provided with an exterior material having a structure in which an opening of a cylindrical film is sealed, and a power generation element sealed in the exterior material. It is intended to provide a possible battery sealing device.

[0009]

A lithium secondary battery according to the present invention is formed into a tubular shape by heat-sealing at least the inner surfaces of a film in which a heat-fusible resin is disposed at at least a heat-sealed portion. An exterior material having a structure in which the opening is heat-sealed with the heat-sealed portion positioned on the upper surface or the lower surface, and a power generation element housed in the exterior material is provided. Things.

[0010] According to such a lithium secondary battery, the heat-sealed portion for making the film into a tubular shape is located on the upper surface of the exterior material,
Since it is located on the lower surface, only two sides of the exterior material can be used as the heat-sealing region. Therefore, the volume loss can be reduced, and the volume energy density can be improved.

[0011] In the lithium secondary battery according to the present invention,
The opening of the tubular film is preferably sealed by heat fusion with both sides folded inside.

[0012] With such a sealing structure, the length of the side of the exterior material that is thermally fused is the same as the width of the exterior material in the area where the power generating element is housed, or is smaller than that. Since the length can be shorter, the volume loss can be further reduced, and the volume energy density can be further improved.

In the battery sealing device according to the present invention, at least the heat-sealing portion of the tubular film having the heat-fusible resin disposed therein is heat-sealed with both sides folded inward. Exterior material having a folded structure, a battery sealing device including a power generation element housed in the exterior material, folding means for folding both sides of the opening of the tubular film inward, A heating and pressurizing means for thermally fusing the opening of the tubular film.

[0014] According to such a sealing device, at least the heat-sealing portion is heat-sealed at the opening of the tubular film in which the heat-sealing resin is disposed with both sides folded inside. Therefore, a battery with improved volume energy density can be provided.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first lithium secondary battery (for example, a polymer lithium secondary battery) according to the present invention will be described in detail with reference to FIGS.

FIG. 1 is a plan view showing a lithium secondary battery according to the present invention, FIG. 2 is a front view showing the lithium secondary battery of FIG. 1, and FIG. 3 is a longitudinal section showing a main part of the lithium secondary battery of FIG. FIG.

That is, a polymer lithium secondary battery is:
The power generating device includes a sheet-shaped power generating element having a band-shaped positive electrode lead 1 and a band-shaped negative electrode lead 2, and a film exterior material 3 in which the power generating element is sealed. The exterior material 3 is formed into a vertically long cylindrical shape by heat-sealing the inner surfaces of a film in which a heat-fusible resin is disposed at least in a heat-sealed portion, and the openings 4a and 4b are heat-sealed. Whether the part 5 is, for example, the center of the upper surface,
It has a structure in which the lower surface is sealed, for example, at the center (central joint seal structure). The positive electrode lead 1 and the negative electrode lead 2 extend from the heat-sealed portion 4a.

The power generating element comprises a positive electrode 8 having a structure in which a porous current collector 6 carries a positive electrode layer 7 containing an active material, a non-aqueous electrolyte and a polymer holding the electrolyte, and a porous current collector. A negative electrode 11 having a structure in which a negative electrode layer 10 containing an active material, a non-aqueous electrolyte and a polymer holding the electrolyte is supported on a body 9
And a separator 12 including a non-aqueous electrolytic solution disposed between the positive electrode layer 7 and the negative electrode layer 10 and a polymer holding the electrolytic solution. The positive electrode 8, the negative electrode 11, and the separator 12 are integrated with a polymer having a function of holding a non-aqueous electrolyte contained therein. The strip-shaped positive electrode terminal 13 is formed by extending the current collector 6 of each of the positive electrodes 8 in a strip shape. on the other hand,
The strip-shaped negative electrode terminal 14 is obtained by extending the current collector 9 of the negative electrode 11 in a strip shape. The positive electrode lead 1 is connected to the two positive terminals 13. The negative electrode lead 2
Is connected to the negative electrode terminal 14.

Hereinafter, the positive electrode, the negative electrode, the separator, and the exterior material of the secondary battery will be described.

(1) Positive Electrode The positive electrode comprises a current collector and a positive electrode layer supported on the current collector and containing a positive electrode active material, a nonaqueous electrolyte, and a polymer holding the electrolyte.

Examples of the positive electrode active material include various oxides (eg, lithium-manganese composite oxides such as LiMn ₂ O ₄ , manganese dioxide, lithium-containing nickel oxides such as LiNiO _2, and lithium-containing cobalt oxides such as LiCoO _2). Oxide, lithium-containing nickel-cobalt oxide, lithium-containing amorphous vanadium pentoxide and the like, and chalcogen compounds (for example, titanium disulfide and molybdenum disulfide). Among them, it is preferable to use a lithium manganese composite oxide, a lithium-containing cobalt oxide, and a lithium-containing nickel oxide.

The non-aqueous electrolyte is prepared by dissolving an electrolyte in a non-aqueous solvent.

As the non-aqueous solvent, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (D
MC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), γ-butyrolactone (γ-
BL), sulfolane, acetonitrile, 1,2-dimethoxyethane, 1,3-dimethoxypropane, dimethyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran and the like. The non-aqueous solvents may be used alone or as a mixture of two or more.

Examples of the electrolyte include lithium perchlorate (LiClO ₄ ) and lithium hexafluorophosphate (L
iPF _6), boric tetrafluoride lithium (LiBF _4), lithium hexafluoroarsenate (LiAsF _6), lithium salts such as lithium trifluoromethane sulfonate (LiCF ₃ SO ₃₎ may be mentioned.

The amount of the electrolyte dissolved in the non-aqueous solvent is desirably 0.2 mol / l to 2 mol / l.

It is desirable that the polymer has a binding function in addition to the function of holding the non-aqueous electrolyte. Examples of such a polymer include a polyethylene oxide derivative, a polypropylene oxide derivative, a polymer containing the derivative, polytetrafluoropropylene, a copolymer of vinylidene fluoride (VdF) and hexafluoropropylene (HFP), and polyvinylidene fluoride ( PVdF) or the like can be used. Among them, VdF
—HFP copolymers are preferred.

[0027] The positive electrode may contain a conductive material from the viewpoint of improving conductivity. Examples of the conductive material include artificial graphite, carbon black (eg, acetylene black), nickel powder, and the like.

As the current collector, for example, a mesh,
Materials having a porous structure such as expanded metal and punched metal can be used. Preferably, the current collector is made of aluminum or an aluminum alloy.

(2) Negative Electrode The negative electrode comprises a current collector and a negative electrode layer supported on the current collector and containing an active material, a non-aqueous electrolyte, and a polymer holding the electrolyte.

Examples of the negative electrode active material include carbonaceous materials that occlude and release lithium ions. Such carbonaceous materials include, for example, those obtained by firing organic polymer compounds (eg, phenolic resin, polyacrylonitrile, cellulose, etc.), those obtained by firing coke and mesophase pitch, and those made by artificial graphite. And carbonaceous materials represented by natural graphite and the like. Among them, it is preferable to use a carbonaceous material obtained by firing the mesophase pitch at a temperature of 500 ° C. to 3000 ° C. in an inert gas atmosphere such as an argon gas or a nitrogen gas under normal pressure or reduced pressure.

As the non-aqueous electrolyte, those similar to those described above for the positive electrode are used.

The polymer desirably has a binding function in addition to the function of holding the non-aqueous electrolyte. As such a polymer, the same type of polymer as that described for the above-described positive electrode can be used.
HFP copolymers are preferred.

As the current collector, for example, a mesh,
Materials having a porous structure such as expanded metal and punched metal can be used. Preferably, the current collector is formed of copper or a copper alloy.

(3) Separator The separator contains a non-aqueous electrolyte and a polymer holding the electrolyte.

Examples of the nonaqueous electrolyte include the same ones as described for the positive electrode.

The polymer desirably has a binding function in addition to the function of holding the non-aqueous electrolyte. As such a polymer, the same type of polymer as that described for the above-described positive electrode can be used.
HFP copolymers are preferred.

The separator preferably further contains a reinforcing material from the viewpoint of improving strength. As the reinforcing material, for example, one or more kinds selected from silicon oxide (SiO ₂ ), mica group, alumina and the like can be used. The form of the reinforcing material can be in the form of particles, fibers or scales. Further, for example, two or more kinds having different forms such as particles and fibers may be mixed and used.

(4) Exterior material This exterior material is made of a film in which a heat-fusible resin is disposed at least on a heat-sealed portion on the inner surface.

Examples of the heat-fusible resin include acid-modified polypropylene, acid-modified polyethylene, and ionomer.

This film preferably has a function of preventing moisture from entering. As such a film,
For example, a laminated film in which a heat-fusible resin is disposed at least in a heat-sealed portion on the inner surface and a metal thin film such as aluminum (Al) is interposed inside can be given.

As a specific example of the exterior material, an acid-modified polypropylene (P) laminated from the heat-sealed portion side to the outer surface is used.
P) / polyethylene terephthalate (PET) / Al foil / PET laminate film; Acid-modified PE / nylon / Al foil / PET laminate film; Ionomer / Ni foil / PE / PET laminate film; Ethylene vinyl acetate (EVA) / PE / Al foil / PET
And a laminated film of ionomer / PET / Al foil / PET. Here, the film other than the acid-modified PE, the acid-modified PP, the ionomer, and the EVA on the side of the heat-sealed portion has moisture resistance, air resistance, and chemical resistance.

The thickness of the exterior material is 0.1 to 0.3 μm
It is preferable to be within the range.

A method for manufacturing this lithium secondary battery will be described with reference to FIGS.

FIG. 4 is a perspective view for explaining a method of manufacturing a lithium secondary battery according to the present invention, and FIG. 5 is a perspective view showing a main part of the lithium secondary battery of FIG.

First, a film in which a heat-fusible resin is disposed at least in a heat-sealed portion is formed into a vertically long cylindrical shape by heat-sealing inner surfaces of the film. The power generating element is housed in the obtained tubular film so that the positive and negative electrode leads 1 and 2 extend from the film. At this time, the heat-sealing portion 5 is located at the center of the upper surface of the tubular film. The opening 4a of the tubular film is sandwiched between a pair of heater blocks 15a and 15b heated to, for example, 120 to 180 ° C., and the opening 4a is thermally fused by applying heat and pressure. Also, the opening 4b of the cylindrical film is thermally fused in the same manner as the opening 4a. As a result, FIG.
3 and FIG. 5 are obtained.

In the first lithium secondary battery according to the present invention described above, the heat-sealed portion 5 formed when forming a vertically long tube is disposed on the upper surface or the lower surface of the sheet-shaped exterior material 3. Therefore, only the short sides 4a and 4b of the exterior material can be used as the heat-sealing area. As a result, the volume loss due to the heat-sealed end can be reduced, and the volume energy density can be improved.

Since the end of the heat-sealed portion 5 does not overlap with both the region where the positive electrode lead 1 is heat-sealed and the region where the negative electrode lead 2 is heat-sealed, the opening 4a
The fusion strength between the lead and the positive and negative electrode leads 1 and 2 can be kept high, and airtightness can be maintained. In addition, when the opening 4a is heat-sealed by heating and pressing in a state where the end of the heat-sealed portion 5 overlaps the positive electrode lead 1 or the negative electrode lead 2 via a film, The thickness of the portion where the heat-sealed portion 5 overlaps becomes thicker than the others, and the pressure applied to that portion is reduced, so that the fusion strength between the positive electrode lead 1 or the negative electrode lead 2 and the opening 4a is reduced. There is fear.

In FIG. 1 described above, the positive electrode layer is supported on both surfaces of the porous current collector, but the positive electrode layer may be supported on only one surface of the porous current collector. Although the current collector of the negative electrode has a porous structure, a metal foil such as a copper foil may be used.

Also, in FIG. 1 described above, an example is described in which a positive electrode, a separator, a negative electrode, a separator and a positive electrode are used in this order, and a power generation element having a five-layer structure is used. , A separator and a negative electrode may be used. The power generating element having a three-layer structure includes a positive electrode having a structure in which a positive electrode layer is supported on both surfaces of a porous current collector, a negative electrode having a structure in which a negative electrode layer is supported on both surfaces of the porous current collector, and a positive electrode and a negative electrode. A positive electrode having a structure consisting of a separator disposed therebetween, or a structure in which a positive electrode layer is supported on one side of a metal foil such as an aluminum foil,
It can have a structure including a negative electrode having a structure in which a negative electrode layer is supported on one side of a metal foil such as a copper foil, and a separator disposed between the positive and negative electrode layers.

The shape of the power generating element is not limited to the above-mentioned sheet shape, but may be applied to any shape of power generating element using a film-made exterior material.

The present invention can be applied not only to the above-described polymer lithium secondary battery, but also to a battery in which a non-aqueous electrolyte is impregnated in a solution state.

Next, a second lithium secondary battery (for example, a polymer lithium secondary battery) according to the present invention will be described in detail with reference to FIGS.

FIG. 6 is a plan view showing the lithium secondary battery according to the present invention, and FIG. 7 is a front view showing the lithium secondary battery of FIG.

That is, the polymer lithium secondary battery is
The power generating element includes a power generating element similar to that described in the first lithium secondary battery described above, and a film exterior member 16 in which the power generating element is sealed. The exterior material 16 is formed into a vertically long tube by heat-sealing the inner surfaces of the film in which the heat-fusible resin is disposed at least in the heat-sealed portion, for example, at the center of the upper surface of the cylindrical film, The heat-sealed portion 17 is positioned, for example, at the center of the lower surface, and in this state, the openings 18a,
18b is sealed (a central joint seal structure). The opening 18a is sealed by folding both sides inward and thermally fusing the positive electrode lead 1 and the negative electrode lead 2 therebetween. On the other hand, the opening 18
b is sealed by heat sealing with both sides folded inside.

As the positive electrode, the negative electrode, the separator, and the exterior material of the secondary battery, those similar to those described in the first lithium secondary battery can be used.

FIGS. 8 to 8 show a method of manufacturing this lithium secondary battery.
This will be described with reference to FIG.

8 and 9 are perspective views for explaining a method of manufacturing a lithium secondary battery according to the present invention, and FIG. 10 is a perspective view showing a main part of the lithium secondary battery of FIG.

First, the sealing device used in this method will be described.

This sealing device includes a battery receiver 19 for positioning an unsealed battery, folding means 20 for folding both sides of the opening of the tubular film inward, and an opening of the tubular film. Heating and pressurizing means 2 for heat fusion
1 is provided. The folding means 20 includes a pair of folding plates 22a and 22b which are inserted on both sides of the openings 18a and 18b of the tubular film, and whose tip is inclined so as to be inserted into the opening end of the tubular film. Air cylinders 23a, 23b serve as first driving means for reciprocating the folding plates 22a, 22b in the horizontal direction.
A pair of holding blocks 24a and 24b arranged above and below the opening of the tubular film;
Air cylinders 25a and 25b are provided as second driving means for reciprocating the a and b in the vertical direction. The heating and pressurizing means 21 is disposed above and below the opening of the tubular film, and includes a pair of heater blocks 26a and 26b having a built-in heater, and each of the heater blocks 26a and 26b.
Air cylinders 27a and 27b are provided as third driving means for reciprocating the 6b vertically.

Each of the folding plates 22a, 22b
Can be formed, for example, from a metal such as stainless steel. The thickness of each of the folding plates 22a and 22b is preferably set to 0.1 to 0.3 mm. If the thickness is less than 0.1 mm, the strength of the plate may be insufficient. On the other hand, if the thickness exceeds 0.3 mm, it may be difficult to fold both sides of the opening of the tubular film inward.

Next, a specific manufacturing method will be described.

First, a film in which a heat-fusible resin is disposed at least in a heat-sealed portion is formed into a vertically long cylindrical shape by heat-sealing inner surfaces of the film. The power generating element is housed in the obtained tubular film so that the positive and negative electrode leads 1 and 2 extend from the film. At this time, the heat-sealing portion 17 is positioned at the center of the upper surface of the tubular film. This is supplied to the battery receiver 19, and the opening 18a from which the positive and negative electrode leads 1 and 2 extend is arranged between the holding blocks 24a and 24b of the folding means 20. By driving the air cylinders 25a and 25b, the holding block 24
The opening 18a is sandwiched so as to maintain the state in which the opening 18a is opened by a and 24b. The opening width is, for example, 2 to 5 mm
It is good to set in the range. Next, the air cylinders 23a and 23b are driven to insert the folding plates 22a and 22b on both sides of the opening 18a, and the opening 18a is folded inward. Subsequently, the air cylinders 25a, 25b are driven, and the openings 18a are crushed by the holding blocks 24a, 24b so that the air cylinders 23a, 23b,
By driving the holding blocks 24a, 25b,
24b and the folding plates 22a and 22b are released.

Next, the air cylinders 27a and 27b of the heating and pressurizing means 21 are driven, and
The heater blocks 26a and 26b heated to 0 ° C. apply heat and pressure across the opening 18a whose both sides are folded inward, so that the opening 18a is melted in a state where both sides are folded inward. To wear. Subsequently, the air cylinders 27a and 27b are driven to move the heater blocks 26a and 26b to release the pressurized state. The opening 18b of the tubular film is also heat-sealed with both sides folded inward in the same manner as in the case of the opening 18a. As a result, FIGS.
0 is obtained.

According to the second lithium secondary battery of the present invention described above, a rectangular laminated film having a heat-fusible resin disposed on at least a heat-sealed portion on the inner surface is heat-sealed between the inner surfaces. In this way, when the openings 18a and 18b are sealed in a state where the heat-sealing portion 17 is located at the center of the upper surface or the center of the lower surface, the openings 18a and 18b are closed on both sides. By heat-sealing in a state of being folded inward, only the short sides of the exterior material 16 can be heat-sealed ends 18a and 18b, and the length of the heat-sealed ends 18a and 18b can be reduced. It can be equal to or shorter than the width of the exterior material in the area where the power generation element is stored. As a result, the volume loss due to the heat-sealed portion can be significantly reduced, so that the volume energy density can be further improved. Note that, as in the first lithium secondary battery described above, the openings 4a and 4
b is heat-sealed without folding both sides inward, the heat-sealed ends 4a and 4b (4b are not shown) as shown in FIG. Exceeds α minutes compared to the width. As a result, the volume occupied by the battery increases, so that a high volume energy density cannot be obtained.

Since the end of the heat-sealed portion 17 does not overlap with both the region where the positive electrode lead 1 is heat-sealed and the region where the negative electrode lead 2 is heat-sealed, the opening 1
The fusion strength between the lead 8a and the positive and negative electrode leads 1 and 2 can be kept high, and the airtightness can be maintained.

The present invention can be applied to a battery in which a non-aqueous electrolyte is impregnated in a solution state, in addition to the above-described polymer lithium secondary battery.

Actually, in the five-layer structure shown in FIG.
55mm long (excluding lead length) and 33m wide
m, a sheet-shaped power generating element having a thickness of 3.3 mm and a theoretical capacity of 540 mAh, and a film having a thickness of 0.15 μm were prepared. The polymer lithium secondary battery shown in FIGS. 1, 6 and 11 described above was prepared. When assembled (the width of the heat-sealed portion was set to 4 mm), the above-described FIG. 1 (first polymer lithium secondary battery) was 68 mm long (excluding the leads protruding from the exterior material) and 37 mm wide. , With a thickness of 3.6 mm,
The volume energy density is 214 Wh / l, and the above-mentioned FIG. 6 (second polymer lithium secondary battery) is 68 mm long (excluding leads protruding from the exterior material) and 3 mm wide.
4mm, thickness 3.6mm, volume energy density 2
In contrast to 33 Wh / l, the above-described FIG. 11 (conventional polymer lithium secondary battery) has a length (excluding leads protruding from the exterior material) of 68 mm, a width of 38 mm, and a thickness of 3.5 mm. , Volume energy density is 209 Wh / l
Was low.

[0068]

As described in detail above, according to the present invention, a lithium secondary battery having an improved volume energy density can be provided. Further, according to the present invention, it is possible to improve the volume energy density of a battery including an exterior material having a structure in which an opening of a cylindrical film is sealed, and a power generation element sealed in the exterior material. It is possible to provide a simple battery sealing device.

[Brief description of the drawings]

FIG. 1 is a plan view showing a lithium secondary battery according to the present invention.

FIG. 2 is a front view showing the lithium secondary battery of FIG. 1;

FIG. 3 is a longitudinal sectional view showing a main part of the lithium secondary battery of FIG. 1;

FIG. 4 is a perspective view for explaining a method for manufacturing a lithium secondary battery according to the present invention.

FIG. 5 is a perspective view showing a main part of the lithium secondary battery of FIG. 1;

FIG. 6 is a plan view showing a lithium secondary battery according to the present invention.

FIG. 7 is a front view showing the lithium secondary battery of FIG. 6;

FIG. 8 is a perspective view for explaining a method of manufacturing a lithium secondary battery according to the present invention.

FIG. 9 is a perspective view for explaining a method of manufacturing a lithium secondary battery according to the present invention.

FIG. 10 is a perspective view showing a main part of the lithium secondary battery of FIG. 6;

FIG. 11 is a plan view showing a conventional polymer lithium secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Positive electrode lead, 2 ... Negative electrode lead, 3 ... Exterior material, 4a, 4b ... Opening, 5 ... Heat fusion part.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Fumimasa Yamamoto, Inventor 3-4-1-10 Minamishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Battery Corporation (72) Toshio Sugawara 3-4-1, Minamishinagawa, Shinagawa-ku, Tokyo No. Toshiba Battery Co., Ltd. (72) Former Takayama Former 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Co., Ltd. (72) Inventor Yasuhiko Hoshina 3-4-1-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Company (72) Inventor Takahiro Kimishima 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Company F-term (reference) 5H011 AA03 CC02 DD06 DD13 FF02 5H029 AJ03 AK03 AK05 AL06 AL07 AM02 AM03 AM04 AM05 AM07 BJ04 CJ02 CJ03 CJ05 DJ02 EJ12

Claims (3)

[Claims] An inner surface of a film in which a heat-fusible resin is disposed at least in a heat-sealed portion is formed into a tubular shape by heat-sealing the inner surfaces of the film, and the opening is formed on the upper surface or the lower surface of the heat-sealed portion. An exterior material having a structure that is heat-sealed in a state where
A power generating element housed in the exterior material. 2. The lithium secondary battery according to claim 1, wherein the opening of the cylindrical film is heat-sealed with both sides folded inward. 3. An exterior material having a structure in which an opening of a tubular film having a heat-fusible resin disposed at least in a heat-fused portion is heat-sealed with both sides folded inward. A battery sealing device including a power generation element housed in the exterior material, a folding unit for folding both sides of an opening of the tubular film inward, and an opening of the tubular film. A battery sealing device comprising: a heating and pressurizing unit for performing heat fusion.