JP2001076689A - Electrochemical device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrochemical device having excellent sealing properties and excellent liquid leakage resistance, and a method for producing the same. SOLUTION: This electrochemical device has an outer bag 20 and an electrochemical element 10 sealed in the outer bag 20, wherein the outer bag 20 has a laminated film having a metal layer and a heat-adhesive resin layer. The electrochemical device 10 is sealed by being sealed with a heat-sealed seal portion between the heat-adhesive resin layers of the outer bag 20, and is led out to the outside through the seal portion. Has,
The lead-out terminals 13 and 14 of the seal portion and the outer bag 2
0, a thermosetting resin layer 41 and an acid-modified polyolefin resin layer 42 are sequentially provided from the lead terminals 13 and 14 side, and the thermosetting resin of the thermosetting resin layer 41 and the acid-modified polyolefin An electrochemical device having a structure having a chemical bond with the polyolefin resin of the resin layer 42 was obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrochemical device such as a polymer lithium secondary battery and an electric double layer capacitor, and a method of manufacturing the same. It relates to a manufacturing method.

[0002]

2. Description of the Related Art In recent years, carbon materials, tin oxide, silicon oxide and the like have been used as negative electrode active materials called lithium secondary batteries.
Secondary batteries are used or considered for various electronic products and electric vehicles. These lithium secondary batteries are
A so-called electrolyte solution in which an electrolyte salt is dissolved in a liquid solvent is used. Batteries using an electrolytic solution have the advantage of low internal resistance, but, on the other hand, have the problem of liability to leak and ignition. To address such problems, for example, a gel polymer solid electrolyte comprising a polymer, an electrolyte salt and a solvent has recently been spotlighted.

[0003] Such a gel-like polymer solid electrolyte is
In some cases, the conductivity is close to that of a liquid and shows a value on the order of 10 ⁻³ S · cm ⁻¹ .

A battery using a solid polymer electrolyte does not leak easily because it does not use a liquid electrolyte. Therefore,
Unlike a conventional battery using a liquid electrolyte, it is not necessary to mechanically caulk with a metal container and a polymer packing in question. In a battery using a polymer solid electrolyte, liquid leakage can be prevented only by using a laminated film composed of a polymer film and a metal foil as an outer bag (container).

However, the adhesion between the lead terminal (metal foil) extending from the inside of the battery to the outside and the polymer film (thermally adhesive resin layer) on the innermost surface of the laminate film is insufficient, and the sealing property of the battery is poor. However, this is not sufficient, and this has been a problem in terms of the cycle life of the battery.

In order to improve the above-mentioned drawbacks, Japanese Patent Application Laid-Open
Japanese Patent No. 289698 discloses a thin sealed battery in which a power generation element containing both positive and negative electrodes and an electrolyte is housed in an outer bag made of a laminate sheet in which a heat-fusible resin layer is fixed to both surfaces of a metal layer. A current collecting tab made of metal is provided on each of the positive and negative electrodes, and each of the current collecting tabs is led out of the battery from a current collecting tab lead-out portion of the outer bag,
And the current collection tab lead-out portion is sealed by heat sealing with a heat-fusible modified resin layer interposed between the current collection tab and the inner surface of the outer package. Is disclosed.

However, the above-mentioned heat-fused modified resin layer has a disadvantage that the sealing property is still insufficient.
Analysis of the cause revealed that the current collection tab (terminal, metal)
It was found that the adhesion to the modified resin layer was reduced by the lithium salt-containing organic electrolyte, but it was very difficult to make a battery so that the electrolyte did not touch the terminal seal during injection. Met.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrochemical device having excellent sealing properties and excellent liquid leakage resistance, and a method for producing the same.

[0009]

This and other objects are attained by the present invention described below. (1) An electrochemical device having an outer bag and an electrochemical element sealed in the outer bag, wherein the outer bag is a laminate film having a metal layer and a heat-adhesive resin layer. The chemical device has a lead-out terminal that is sealed and sealed by a heat-sealed seal portion between the heat-adhesive resin layers of the outer bag, and leads to the outside through the seal portion, and the lead-out of the seal portion. A thermosetting resin layer and an acid-modified polyolefin resin layer are sequentially provided from the lead-out terminal side between the terminal and the outer package, and the thermosetting resin and the acid-modified polyolefin resin layer of the thermosetting resin layer are provided. An electrochemical device having a chemical bond with a polyolefin resin. (2) The electrochemical device according to (1), wherein the chemical bond is a covalent bond reaction between a hydroxyl group or an amino group of the thermosetting resin and a reactive group of the acid-modified polyolefin resin. (3) The electrochemical device according to the above (1) or (2), wherein the acid-modified polyolefin resin is an acid-modified polypropylene resin obtained by graft polymerization of maleic anhydride. (4) The electrochemical device according to any one of (1) to (3), wherein the thermosetting resin is an epoxy resin. (5) The electrochemical device according to any one of (1) to (3), wherein the thermosetting resin is a urethane resin. (6) The above (1) to lithium ion secondary battery
The electrochemical device according to any one of (5). (7) The above (1) to the electric double-layer capacitor
The electrochemical device according to any one of (5). (8) The electrochemical element is housed in an outer bag that is a laminate film having a metal layer and a thermoadhesive resin layer, and the lead terminals connected to the positive and negative electrodes of the electrochemical element are connected to the thermoadhesive resin of the outer bag. A method for manufacturing an electrochemical device in which a seal portion is formed by thermal bonding sandwiching between layers and sealing is performed, and a thermosetting resin layer is sequentially formed from the lead terminal side to a portion corresponding to the seal portion of the lead terminal, A lead terminal coating step of laminating and thermally bonding an acid-modified polyolefin resin layer, and impregnating the polymer film between the positive and negative electrodes of the electrochemical device after the lead terminal coating step with an electrolytic solution to form a polymer solid electrolyte. A method of manufacturing an electrochemical device, comprising: (9) The method for producing an electrochemical device according to (8), wherein the electrochemical device according to any one of (1) to (7) is obtained.

[0010]

As a result of repeated studies, the present inventor has covered a lead-out terminal made of metal with a thermosetting resin layer, further covered with an acid-modified polyolefin resin layer, and then laminated with an outer bag. As a result, it has been found that the resistance of the seal portion to the electrolytic solution is dramatically improved.

That is, when the inner surface of the outer bag is a heat-adhesive resin layer, and a thermosetting resin layer and an acid-modified polyolefin resin layer are arranged between the heat-adhesive resin layer and the lead-out terminal, The adhesiveness between the heat-adhesive resin layer on the inner surface and the lead terminals (metals such as aluminum and nickel) is improved. Between the acid-modified polyolefin resin layer and the heat-adhesive resin of the outer bag, the strength at the time of fusion does not decrease even if the electrolytic solution is present, so that the sealing property can be maintained, so that leakage is prevented,
An electrochemical device having good cycle life and high-temperature storage characteristics can be obtained.

[0012]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic structure of the electrochemical device of the present invention. FIG. 2 shows FIG.
FIG. 3C is a cross-sectional view taken along the line AA in FIG. 3C, showing a cross-sectional structure of a seal portion including a lead terminal.

The electrochemical device 1 shown in FIG.
The lead-out terminals 13 and 14 of the electrochemical element 10 shown in FIG. 1A are placed in an outer bag 20 formed in a bag shape by the first seal portion 21 shown in FIG. It is stored in a state of protruding to the outside, and the open end surface of the outer bag 20 is sealed by heat fusion with the lead-out terminals 13 and 14 interposed therebetween to form a second seal portion 22. Electrochemical device 1
Has a structure in which the electrochemical element 10 is sealed in the outer bag 20 and the lead-out terminals 13 and 14 project from the second seal portion 22 to the outside.

The electrochemical element 10 includes positive and negative electrodes 11, 12 formed of a current collector such as an aluminum foil or a copper foil, and a solid polymer electrolyte (not shown). As shown in FIG. 1A, lead terminals 13 and 14 are connected to the positive and negative electrodes 11 and 12, respectively. Outgoing terminals 13, 14
Is a metal such as aluminum, copper, nickel, and stainless steel, and is configured in a lead shape having a rectangular or circular cross section. The lead-out terminals 13 and 14 conceptually have seal portions 13a and 14a in regions covered by the second seal portion 22, respectively.

The outer bag 20 has a laminated film 3 in which a polyolefin resin layer such as polypropylene or polyethylene or a heat-resistant polyester resin layer as a heat-adhesive resin layer is laminated on both sides of a metal layer such as aluminum.
0. As shown in FIG. 1 (b), the outer bag 20 heat-bonds the two laminated films 30 to each other at the heat-adhesive resin layers on the three end surfaces thereof to form a first seal portion 21. It is formed in a bag shape with one side opened. Alternatively, a single laminated film may be folded back and the both end faces may be thermally bonded to form a seal portion to form a bag.

In the second seal portion 22 of the electrochemical device 1 of the present invention, as shown in FIG. 2, the lead-out terminals 13 and 14 are sandwiched between the laminate films 30 constituting the outer bag 20. 14 and laminated film 30
A thermosetting resin layer 41 directly laminated on the lead-out terminal, and a thermosetting resin layer 41
And an intermediate layer 40 laminated in the order of the acid-modified polyolefin resin layer 42 covering the resin.

Heretofore, the adhesion between the lead terminal formed of a metal foil and the heat-adhesive resin layer forming the outer bag has been insufficient. In the electrochemical device 1 of the present invention, the thermosetting resin layer 41 is provided with the sealing portions 13a of the lead terminals 13 and 14,
14a is directly laminated to cover metal (aluminum,
(Copper, nickel, stainless steel, etc.) and the acid-modified polyolefin resin, and is extremely effective in pulling out the lead-out terminal from the laminate bag and sealing.

The acid-modified polyolefin resin layer 42 functions as a heat-adhesive resin layer because it has excellent mutual adhesion with the polyolefin resin layer as the heat-adhesive resin layer of the laminate film 30. Acid-modified polyolefin resin layer 42
Is preferably about 3 to 100 μm. Examples of the acid-modified polyolefin resin include acid-modified polyethylene such as carboxylic acid, and acid-modified polypropylene obtained by graft-polymerizing maleic anhydride, and acid-modified polypropylene is particularly preferable. Due to compatibility, when the heat-adhesive resin layer of the laminate film 30 is made of polyethylene, the polyolefin resin layer 42 of the intermediate layer 40 is preferably made of polyethylene, and when the heat-adhesive resin layer of the laminate film 30 is made of polypropylene. Is the intermediate layer 40
It is preferable that the polyolefin resin layer 42 is also of a polypropylene type from the viewpoint of adhesiveness.

These resins preferably have a reactive group for chemically bonding with the following thermosetting resin, specifically a carboxyl group or the like.

As such a resin, an acid-modified polypropylene obtained by graft-polymerizing the above maleic anhydride is known, and is sold, for example, by Mitsui Chemicals, Inc. under the trade name Admer. Among these admers, a polypropylene-type admer is particularly preferable, and particularly, as a homopolymer, QF305 (melting point: 1)
60F), QF500 (melting point: 165 ° C), as a copolymer with ethylene, QF551 (melting point: 135 ° C),
QB540 (melting point: 150 ° C.), QB550 (melting point: 1)
40 ° C.) and QE060 (melting point: 139 ° C.).

In the present invention, a thermosetting resin layer 41 is further coated as a base layer to improve the adhesion between the acid-modified polyolefin resin 42 and the lead terminals 13 and 14.

Examples of the thermosetting resin layer 41 include an epoxy resin and a urethane resin. Thermosetting resin layer 41
Are provided between the metal (outgoing terminal) and the acid-modified polyolefin resin to improve their adhesion, and therefore, the seal portions 13a, 14 of the outgoing terminals 13, 14 are provided.
A size sufficient to cover a is sufficient. Thermosetting resin layer 4
The thickness of 1 is preferably about 1 to 50 μm.

The thermosetting resin preferably has a hydroxyl group or an amino group. This hydroxyl group or amino group is
A chemical bond is formed with the reactive group of the acid-modified polyolefin resin. Such a hydroxyl group and an amino group may be contained in the thermosetting resin itself, or may be contained in the presence of a curing agent, a reaction accelerator, etc., and may be finally introduced into the thermosetting resin. May be something.

Specifically, bisphenol A type is preferable as the epoxy resin.
Type, brominated bisphenol A type, hydrogenated bisphenol A
Type, bisphenol S type, bisphenol AF type and the like are also preferable. As the curing agent, metaxylene diamine, isophorone diamine, or the like is preferable as a polyamine-based curing agent.
As the lower amine imidazole Lewis acid, benzyldimethylamine and the like are preferable.

The lead terminal covering step of covering the lead terminal seal portions 13a and 14a with the intermediate layer 40 composed of such a thermosetting resin layer / acid-modified polyolefin resin layer is as follows.
For example, a thermosetting resin is used as the lead terminal sealing portions 13a, 13a.
a, applied to some extent, preferably 50 to 90%
There is a method of thermally curing to a certain extent, and then thermally welding an acid-modified polyolefin film on the thermosetting resin layer. At the time of this lead-out terminal covering step, the lead-out terminal may be welded or bonded to the battery or the electric double layer capacitor before the electrolyte is injected, or may be a single terminal. In any case, it is necessary to form and arrange the intermediate layer 40 of the present invention on the lead-out terminals 13 and 14 before injecting the electrolytic solution.

After the lead-out terminal covering step, the battery positive electrode and the battery negative electrode having the lead-out terminal subjected to the above treatment and an element having a polymer film are immersed in a lithium salt-containing organic electrolyte to be impregnated with an electrolyte. A liquid injection step is performed in which the polymer film is converted into a polymer solid electrolyte to produce an electrochemical device.

Thereafter, the electrochemical element is inserted into a laminate bag made of metal and resin, and the opening is heat-sealed.
An electrochemical device is obtained by a sealing process.

In order to ensure insulation between the metal foil forming the laminate film and the lead-out terminal, the laminate film forming the outer package is formed from a heat-adhesive resin layer / polyester resin layer / metal foil / polyester from the inner layer side. It is preferable to use a laminate film having a laminated structure of resin layers. By using such a laminated film, the high melting point polyester resin layer remains without melting at the time of thermal bonding, so that a separation distance between the lead terminal and the metal foil of the outer package can be ensured, and insulation can be ensured. . Therefore, the thickness of the polyester resin layer of the laminate film is preferably about 5 to 100 μm.

The electrochemical device of the present invention can be used as a lithium secondary battery or an electric double layer capacitor as described below.

<Lithium secondary battery> Lithium 2 of the present invention
Although the structure of the secondary battery is not particularly limited, it is generally composed of a positive electrode, a negative electrode, and a solid polymer electrolyte, and is suitably applied to a sheet-type battery, a cylindrical battery, and the like.

The electrode to be combined with the polymer solid electrolyte may be appropriately selected from those known as electrodes for a lithium secondary battery, and is preferably used as an electrode active material and a gel electrolyte, and if necessary, a conductive auxiliary. Is used.

For the negative electrode, a negative electrode active material such as a carbon material, lithium metal, lithium alloy or oxide material is used. For the positive electrode, an oxide or carbon material capable of intercalating / deintercalating lithium ions is used. It is preferable to use such a positive electrode active material as described above. By using such an electrode, a lithium secondary battery having excellent characteristics can be obtained.

The carbon material used as the electrode active material may be appropriately selected from, for example, mesocarbon microbeads (MCMB), natural or artificial graphite, resin fired carbon material, carbon black, carbon fiber, and the like. These are used as powders. Above all, graphite is preferred, and its average particle size is preferably 1 to 30 μm, particularly preferably 5 to 25 μm. If the average particle size is too small, the charge / discharge cycle life tends to be short and the variation in capacity (individual difference) tends to be large. If the average particle size is too large, the dispersion of the capacity becomes extremely large, and the average capacity becomes small. It is considered that the capacity variation occurs when the average particle size is large because the contact between the graphite and the current collector and the contact between the graphites vary.

When lithium ions are intercalated
Intercalatable oxides include lithium
Composite oxides are preferred, for example, LiCoO_Two, LiM
n_TwoO _Four, LiNiO_Two, LiV_TwoO_FourAnd the like.
The average particle size of these oxide powders is about 1 to 40 μm.
It is preferred that

If necessary, a conductive additive is added to the electrode. Preferred examples of the conductive auxiliary agent include metals such as graphite, carbon black, carbon fiber, nickel, aluminum, copper, and silver. Particularly, graphite and carbon black are preferable.

The electrode composition is as follows: active material: conductive auxiliary agent: gel electrolyte = 30 to 90: 3 to 10: 1 by weight in the positive electrode.
The range of 0 to 70 is preferable. In the negative electrode, active material: conductive auxiliary agent: gel electrolyte = 30 to 90: 0 to 10: 1 by weight ratio.
A range from 0 to 70 is preferred. The gel electrolyte is not particularly limited, and a commonly used gel electrolyte may be used. Also,
An electrode containing no gel electrolyte is also preferably used. In this case, a fluorine resin, a fluorine rubber, or the like can be used as the binder, and the amount of the binder is about 3 to 30 wt%.

In the production of an electrode, first, an active material and, if necessary, a conductive auxiliary are dispersed in a gel electrolyte solution or a binder solution to prepare a coating solution.

Then, this electrode coating solution is applied to a current collector. The means for applying is not particularly limited, and may be determined as appropriate according to the material and shape of the current collector. Generally, a metal mask printing method, an electrostatic coating method, a dip coating method, a spray coating method, a roll coating method, a doctor blade method, a gravure coating method, a screen printing method, and the like are used.
Thereafter, if necessary, a rolling treatment is performed by a flat plate press, a calender roll, or the like.

The current collector may be appropriately selected from ordinary current collectors according to the shape of the device used by the battery, the method of disposing the current collector in the case, and the like. Generally, aluminum or the like is used for the positive electrode, and copper, nickel, or the like is used for the negative electrode.
Note that a metal foil, a metal mesh, or the like is generally used as the current collector. Although the metal mesh has lower contact resistance with the electrode than the metal foil, a sufficiently low contact resistance can be obtained even with the metal foil.

Then, the solvent is evaporated to produce an electrode. The coating thickness is preferably about 50 to 400 μm.

The polymer film is made of, for example, PEO (polyethylene oxide), PAN (polyacrylonitrile)
And a polymer microporous membrane such as PVDF (polyvinylidene fluoride).

Such a positive electrode, a polymer film, and a negative electrode are laminated in this order and pressed to form a battery body.

The electrolyte for impregnating the polymer membrane generally comprises an electrolyte salt and a solvent. As the electrolyte salt, for example, Li
BF ₄ , LiPF ₆ , LiAsF ₆ , LiSO ₃ C
Lithium salts such as F ₃ , LiClO ₄ , and LiN (SO ₂ CF ₃ ) ₂ can be used.

The solvent of the electrolytic solution is not particularly limited as long as it has good compatibility with the above-mentioned solid polymer electrolyte and electrolyte salt. In a lithium battery or the like, a polar organic solvent which does not decompose even at a high operating voltage is used. Solvents, for example, carbonates such as ethylene carbonate (abbreviation EC), propylene carbonate (abbreviation PC), butylene carbonate, dimethyl carbonate (abbreviation DMC), diethyl carbonate, ethyl methyl carbonate, etc., tetrahydrofuran (THF), 2-methyltetrahydrofuran and the like A cyclic ether, a cyclic ether such as 1,3-dioxolan, 4-methyldioxolan, a lactone such as γ-butyrolactone, a sulfolane, and the like are preferably used. 3-Methylsulfolane, dimethoxyethane, diethoxyethane, ethoxymethoxyethane, ethyldiglyme and the like may be used.

When it is considered that the electrolyte is composed of the solvent and the electrolyte salt, the concentration of the electrolyte salt is preferably 0.3 to 2 mol.
l / l. Usually, it exhibits the highest ionic conductivity at around 1 mol / l.

When a microporous polymer film is immersed in such an electrolytic solution, the polymer film absorbs the electrolytic solution and gels to form a solid polymer electrolyte.

When the composition of the polymer solid electrolyte is expressed as polymer / electrolyte, the ratio of the electrolyte is preferably 40 to 90% by weight in view of the strength of the membrane and the ionic conductivity.

<Electric Double Layer Capacitor> Electric 2 of the present invention
Although the structure of the multilayer capacitor is not particularly limited, usually, a pair of polarizable electrodes are arranged via a polymer solid electrolyte, and an insulating gasket is arranged around the polarizable electrode and the polymer solid electrolyte. I have. Such electricity 2
The multilayer capacitor may be any type called a coin type, a sheet type, a laminated type, or the like.

As the polarizable electrode, activated carbon, activated carbon fiber or the like is used as an active material, and a fluorocarbon resin,
Add fluoro rubber etc. Then, it is preferable to use the mixture formed on a sheet-like electrode. The amount of the binder is about 5 to 15 wt%. Further, a gel electrolyte may be used as the binder.

The current collector used for the polarizable electrode may be a conductive rubber such as a conductive butyl rubber or the like, or may be formed by spraying a metal such as aluminum or nickel. A metal mesh may be provided.

The electric double layer capacitor is formed by combining the above-mentioned polarizable electrode and the solid polymer electrolyte.

The polymer film is made of, for example, PEO (polyethylene oxide), PAN (polyacrylonitrile)
And a polymer microporous membrane such as PVDF (polyvinylidene fluoride).

As the electrolyte salt, (C ₂ H ₅ ) ₄ NB
F ₄ , (C ₂ H ₅ ) ₃ CH ₃ NBF ₄ , (C ₂ H ₅ ) ₄ PB
F _4, and the like.

The non-aqueous solvent used in the electrolytic solution may be any of various known ones, and propylene carbonate, ethylene carbonate, γ-
Butyrolactone, acetonitrile, dimethylformamide, 1,2-dimethoxyethane, sulfolane alone or a mixed solvent is preferred.

The concentration of the electrolyte in such a non-aqueous solvent-based electrolyte solution may be 0.1 to 2 mol / l.

When a microporous polymer film is immersed in such an electrolytic solution, the polymer film absorbs the electrolytic solution and gels to form a solid polymer electrolyte.

When the composition of the solid polymer electrolyte is represented by polymer / electrolyte, the ratio of the electrolyte is preferably 40 to 90% by weight in view of the strength of the membrane and the ionic conductivity.

As the insulating gasket, an insulator such as polypropylene or butyl rubber may be used.

[0059]

[Example 1] (Production of battery) Aluminum foil and nickel foil having a width of 4 mm, a length of 50 mm and a thickness of 0.1 mm were prepared as terminal materials. As the epoxy resin which is a thermosetting resin, “Epicoat 828” and “Epomate B002” (trade names) of Yuka Shell Epoxy Co., Ltd. were used. Epicoat 828 is a bisphenol A type epoxy resin, and epomate B002 is a modified complex diamine. The epicoat 828: epomate B002: toluene = 20: 10: 70 parts by weight was mixed and sprayed on the position of the seal portion of the lead-out terminal. Thereafter, the mixture is cured at 60 ° C. for 1 hour, and further, an acid-modified polypropylene film, which is an acid-modified polyolefin resin (Admer QE06, Mitsui Chemicals, Inc.)
0 and a thickness of 80 μm) were thermocompression-bonded to form a lead terminal. Thereafter, the terminals were further cured at 80 ° C. for 3 hours.

The electrodes were LiCoO ₂ , carbon black (HS-100, manufactured by Denki Kagaku Kogyo), PVDF
(Polyvinylidene fluoride) was applied to an aluminum foil by a doctor blade method to prepare. The negative electrode is mesocarbon microbeads (MCMB), HS-10
0, made of PVDF was applied to copper foil by a doctor blade method. A microporous PVDF membrane was used as a polymer solid electrolyte. Positive and negative electrodes are 31 mm wide and 41 mm long
Cut into pieces. The separator was cut into a width of 33 mm and a length of 43 mm.

The battery element was prepared as follows. First, the positive electrode and the separator were laminated and laminated by hot pressing.
The laminating conditions were 150 ° C. and a pressure of 5 kgcm ⁻² for 2 minutes. A negative electrode was laminated thereon and laminated similarly.

The aluminum current collector of this battery element was resistance-welded with the above-described aluminum output terminal, and the copper current collector was similarly resistance-welded with the above-mentioned nickel output terminal. This battery element is EC
(Ethylene carbonate) and DMC (dimethyl carbonate) were immersed for 30 minutes in 330 ml of an electrolyte obtained by dissolving 1 M of LiPF _{6 in} a mixed solvent of 1: 2 by volume. After taking out the battery body from the electrolyte, the electrolyte adhering to the electrode surface was wiped off. This battery element absorbed the electrolytic solution and became a gel state. PET (12 μm) / aluminum (20 μm) / PET (12 μm) / PP (80 μm)
The battery element was inserted into a laminate bag (with the innermost layer being PP), and the opening was heat-sealed to produce 200 sheet-type polymer lithium secondary batteries. In the above, PET: polyethylene terephthalate, PP: polypropylene.

Table 1 shows the number of leaks when each sample was fully charged and stored at room temperature for 60 days. As is clear from Table 1, all the batteries of the present invention did not cause liquid leakage.

Example 2 As a urethane resin, trade names "AD-506S" and "CAT-RTl" of Toyo Morton Co., Ltd. were used. AD-506S is a polyester resin, and CAT-RTl is isophorone diisocyanate (IPDI). When these are mixed and cured, a urethane resin is obtained. AD-506S: CAT-RTl = 1
The mixture was mixed to give 00: 5 parts by weight, diluted with ethyl acetate so as to have a sprayable viscosity, and sprayed to the terminals. After curing this at 80 ° C for 30 minutes, Admer Q
E060 was heat-sealed and used as a terminal. Otherwise, a sheet-type polymer lithium ion secondary battery was manufactured and evaluated in the same manner as in Example 1. As a result, as shown in Table 1, the number of leaked samples was five.

Example 3 As a urethane resin, trade names "AD-335A" and "CAT-10" of Toyo Morton Co., Ltd. were used. AD-338A is a polyester resin, and CAT-10 is toluene diisocyanate (TDI). When these are mixed and cured, they become urethane grease. AD-335A: CAT-10 = 10
The mixture was mixed at 0: 6 parts by weight, diluted with a mixed solvent of methyl ethyl ketone: toluene = 1: 1 so as to have a sprayable viscosity, and sprayed to a terminal. After this was cured at 80 ° C. for 30 minutes, a polypropylene film (Admer QE060: thickness 80 μm) was thermocompressed thereon and used as a terminal. Otherwise, a sheet-type polymer lithium ion secondary battery was produced and evaluated in the same manner as in Example 1. As a result, as shown in Table 1, 10 batteries leaked.

Comparative Example 1 As a heat-fusible resin, only Admer QEO60 (trade name, manufactured by Mitsui Chemicals, Inc.) was thermocompression-bonded onto a terminal, and this was used as a terminal. Admer QEO60 is an acid-modified polypropylene. Others are described in Example 1.
A sheet-type polymer lithium ion secondary battery was prepared and evaluated in the same manner as described above. As a result, as shown in Table 1, the number of leaked samples was 100/200.

[0067]

[Table 1]

From the above examples, it can be seen that as a result of the improved sealing performance of the battery according to the present invention, there is an effect of preventing leakage of the electrolytic solution.

Example 4 (Preparation of Capacitor) Active Material: Activated Carbon Powder, Conductive Aid: Acetylene Black, Polymer: PVDF [KynarFlex 2801 (Elf Atchem)], (Polyvinylidene fluoride and 6 Copolymer with propylene fluoride), solvent: acetone by weight ratio, active material: conduction aid: polymer: solvent = 8:
A polymer solution was prepared by mixing at a ratio of 1: 1: 15, and this was applied to an aluminum foil to form positive and negative electrodes.

A microporous PVDF membrane was used as a polymer solid electrolyte.

Next, the positive electrode and the negative electrode were laminated via a solid polymer electrolyte, and the positive and negative electrodes were welded with the aluminum terminals used in Example 1 and then impregnated with an electrolytic solution. did. The electrolyte used was a solution prepared by dissolving 4-ethylammonium tetrafluoroborate at a concentration of 1 M in propylene carbonate.

Otherwise, the procedure of Example 1 was followed to obtain a capacitor 1. Further, capacitors 2 and 3 and comparative capacitor 1 were produced in the same manner as in Examples 2 and 3 and Comparative Example 1.

When the obtained capacitors 1, 2, 3 and the comparative capacitor 1 were evaluated in the same manner as in Example 1, almost the same results were obtained.

[0074]

As described above, according to the electrochemical device of the present invention, it is possible to provide an electrochemical device having excellent sealing properties and excellent liquid leakage resistance, and a method for producing the same.

[Brief description of the drawings]

FIG. 1 shows the structure of the electrochemical device of the present invention,
(A) is a plan view showing electrodes and lead-out terminals constituting an electrochemical element, (b) is a plan view showing an outer bag, and (c) is an electrochemical device formed by enclosing the electrochemical element in an outer bag. FIG.

FIG. 2 is a sectional view taken along line AA of FIG. 1 (c).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrochemical device 10 Electrochemical element 11, 12 Electrode 13, 14 Lead-out terminal 13a, 14a Seal part 20 Outer bag 21 First seal part 22 Second seal part 30 Laminate film 40 Intermediate layer 41 Thermosetting resin layer 42 Acid modification Polyolefin resin layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H011 AA17 CC02 CC06 CC10 DD13 EE04 FF04 GG01 HH02 HH13 5H029 AJ04 AJ05 AJ15 AK02 AK03 AK06 AK07 AL02 AL06 AL12 AM02 AM03 AM04 AM07 AM16 BJ04 CJ05 DJ02 DJ03 DJ05 EJ01

Claims (9)

[Claims] 1. An electrochemical device having an outer bag and an electrochemical element sealed in the outer bag, wherein the outer bag is a laminate film having a metal layer and a heat-adhesive resin layer, The electrochemical device has a lead-out terminal that is sealed and sealed by a heat-sealed seal portion between the heat-adhesive resin layers of the outer bag, and is led out through the seal portion. A thermosetting resin layer and an acid-modified polyolefin resin layer are sequentially provided from the lead-out terminal side between the lead-out terminal and the outer package, and the thermosetting resin and the acid-modified polyolefin of the thermosetting resin layer are provided. An electrochemical device having a chemical bond with a polyolefin resin of a resin layer. 2. The electrochemical device according to claim 1, wherein the chemical bond is a covalent bond reaction between a hydroxyl group or an amino group of the thermosetting resin and a reactive group of the acid-modified polyolefin resin. 3. The electrochemical device according to claim 1, wherein the acid-modified polyolefin resin is an acid-modified polypropylene resin obtained by graft polymerization of maleic anhydride. 4. The electrochemical device according to claim 1, wherein said thermosetting resin is an epoxy resin. 5. The electrochemical device according to claim 1, wherein the thermosetting resin is a urethane resin. 6. A lithium ion secondary battery according to claim 1.
The electrochemical device according to any one of items 1 to 5, 7. An electric double-layer capacitor.
5. The electrochemical device according to any one of 5. 8. An electrochemical device is housed in an outer bag which is a laminate film having a metal layer and a heat-adhesive resin layer, and a lead terminal connected to both positive and negative electrodes of the electrochemical device is provided.
A method for manufacturing an electrochemical device in which a seal portion is formed by thermal bonding between thermal adhesive resin layers of the outer package and sealed, and a portion corresponding to the seal portion of the lead terminal is provided from the lead terminal side. A lead terminal coating step of sequentially laminating and thermally bonding a thermosetting resin layer and an acid-modified polyolefin resin layer; and an electrolytic solution on the polymer film between the positive and negative electrodes of the electrochemical device after the lead terminal coating step has been completed. And a liquid injection step of obtaining a solid polymer electrolyte by impregnating the polymer electrolyte. 9. The method for manufacturing an electrochemical device according to claim 8, wherein the electrochemical device according to claim 1 is obtained.