JP2001176554A - Method of manufacturing electrochemical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an electrochemical element comprising a separator made of a porous film with a solid electrolyte filling in the pores and a pair of electrodes disposed by way of porous film productively and easily. SOLUTION: First, a porous film with pores for the separator for the electrochemical element is prepared. The porous film holds an electrolytic salt, a solvent for the electrolytic salt, and a reversible gelatinizer to form a reversal sol-gel electrolytic composition. Then, a device of the electrochemical element, which has a pair of electrodes disposed opposite to each other by way of the porous film, is formed and the device is soaked in an electrolyte made of the electrolytic salt and the solvent for the electrolytic salt. Then the reversible gelatinizer is dissolved in the electrolyte to be the sol of the reversible sol-gel electrolytic composition. After that, the sol is gelatinized and the pores of the porous film are filled with a solid electrolyte made of the gel of the reversible sol-gel electrolytic composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrochemical device, and more particularly, to a method in which a pair of electrodes are opposed to each other with a separator interposed therebetween, and the separator is filled with a solid electrolyte in its pores. The present invention relates to a method for easily manufacturing an electrochemical device with high productivity. Such an electrochemical element can be suitably used as an element such as a battery, a capacitor, or a capacitor.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become more portable, there has been an increasing demand for higher capacity and lighter weight batteries as power supplies. And high-capacity secondary batteries such as lithium-ion batteries are becoming widespread. However, since these conventional batteries use a liquid as an electrolyte, when the battery container is damaged, there is a possibility that the battery leaks. Particularly, in a lithium ion secondary battery, since a non-aqueous (organic) solvent is used for an electrolytic solution, an accident such as breakage of an electronic device using the battery itself is likely to occur when a liquid leak occurs.

In recent years, in order to improve the energy density of a battery, a lithium ion secondary battery using a laminated film as an outer bag instead of a conventional metal outer can has been proposed. In such a laminated film bag type battery, compared to a battery using a metal outer can, the laminated film comes into contact with other parts of the battery to form a hole, or the opening of the bag is incomplete. It is highly possible that the electrolyte solution leaks out of the bag due to a simple sealing or the like.

On the other hand, capacitors and capacitors are often used in recent electronic devices. In these cases, since a non-aqueous (organic) solvent is conventionally used as an electrolytic solution, the outer package is similarly formed. When the battery is damaged by impact, heat, or the like, the electrolyte may leak to the outside, and even the surrounding electronic devices may be damaged.

Therefore, in order to solve such a problem, it has long been proposed in the field of lithium batteries to use a solid electrolyte instead of a liquid electrolyte. As such a solid electrolyte, for example, a polyalkylene ether-based polymer component such as polyethylene oxide, polypropylene oxide, or polyethylene glycol, or a polymer component such as polyacrylonitrile, polyphosphazene, or polymethyl methacrylate containing a lithium salt. Things are known.

However, according to the batteries using these conventional solid electrolytes, the solid electrolyte has a significantly lower ionic conductivity than the liquid electrolyte, so that the battery has a high internal resistance, so that a practical charge / discharge operation is possible. Can not do. If the shape of the electrode changes due to charging and discharging, the solid electrolyte cannot follow such a change in the shape of the electrode. It cannot be discharged.

In order to improve the low ionic conductivity of such a solid electrolyte, for example, it has been proposed to blend an organic solvent such as propylene carbonate or γ-butyrolactone as a plasticizer into the solid electrolyte.

For example, J. Electrochem. Soc., Vol.
7, 1657-1658 (1990) proposes a sheet-like gel electrolyte obtained by gelling an organic electrolytic solution comprising a mixed solvent of propylene carbonate and ethylene carbonate in which lithium perchlorate is dissolved with polyacrylonitrile. . JP-A-11-16579 proposes a gel electrolyte comprising polyacrylonitrile, an electrolyte salt and a non-aqueous solvent. JP-A-8-298126 proposes a gel electrolyte using polyethylene oxide or polypropylene oxide as a polymer component and using γ-butyrolactone as a solvent.

As described above, an electrolyte obtained by mixing an organic solvent with a conventional solid electrolyte is generally called a gel electrolyte. Such gel electrolytes have somewhat improved ionic conductivity as compared to the conventional solid electrolytes as described above, but are still lower than liquid electrolytes.
Therefore, when such a gel electrolyte is used in a battery, the internal resistance is not sufficiently reduced, and when the shape of the electrode changes, the internal resistance is still low. Can't keep up with change.

Further, in general, in order to obtain a sufficient gel state in the gel electrolyte, it is necessary to set the compounding ratio of the polymer component to about 20% by weight or more. For example, since the conductivity is lower than that of the liquid electrolyte, the internal resistance of the battery increases, and the charge / discharge characteristics deteriorate. This tendency is particularly remarkable at a low temperature of 0 ° C. or lower.

For example, when an electrode in a battery is made of an aggregate of granular or flaky active materials and has a gap between them, or when it is made of a porous material having a gap, the electrode is formed in such a gap. Due to the presence of the electrolyte,
For the first time, the transfer of reactants at the electrode-electrolyte interface is performed smoothly, and sufficient charge and discharge can be performed. Therefore, in general, when manufacturing an electrochemical element containing a solid electrolyte or a gel electrolyte together with an electrode, it is necessary to previously fill the electrolyte with a void in the electrode. Thus, conventionally, the production of an electrochemical device containing a solid electrolyte together with an electrode requires many steps, resulting in poor productivity and increased production cost.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in an electrochemical device containing a solid electrolyte, and is directed to a porous membrane having pores filled with a solid electrolyte. It is an object of the present invention to provide a method capable of easily obtaining, with good productivity, an electrochemical device having a separator and a pair of electrodes disposed via the separator.

[0013]

According to the present invention, there is provided an electrolyte comprising a reversible gelling agent capable of forming a reversible sol-gel electrolyte composition together with an electrolyte salt and a solvent for the electrolyte salt. A porous membrane having pores for a chemical element separator is prepared, and a pair of electrodes are disposed to face each other to form a work in process of the electrochemical element. After impregnating the in-process product with the solvent comprising the solvent of the above, and dissolving the reversible gelling agent in the electrolyte to form a sol of the reversible sol-gel electrolyte composition, A method for producing an electrochemical device is provided, which comprises gelling, and thus, filling the pores of the porous membrane with a solid electrolyte comprising a gel of the reversible sol-gel electrolyte composition.

[0014]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a reversible sol-gel electrolyte composition comprises a reversible gelling agent, an electrolyte salt and a solvent for the electrolyte salt, that is, a solvent that dissolves the electrolyte salt, preferably , A non-aqueous (organic) solvent. As described above, the reversible gelling agent is a substance that imparts reversible sol-gel properties to the obtained composition when the electrolyte is mixed with an electrolytic solution dissolved in a solvent.

That is, in the present invention, the term “reversible gelling agent” refers to a composition obtained by mixing a solvent in which an electrolyte salt is dissolved, preferably a non-aqueous solvent solution (ie, a non-aqueous electrolyte). However, when heated to a temperature above room temperature (25 ° C.), for example, but not limited to, 40-100 ° C., a uniform solution is formed and the solution is allowed to cool to room temperature (25 ° C.).
° C) means a substance that forms a gel composition reversibly when cooled to, in principle, reversibly binds and dissociates or reversibly mobilizes and immobilizes according to changes in temperature, pressure, etc. A substance capable of reversibly performing the above-mentioned bond and dissociation or mobility and immobilization by intermolecular or intramolecular interactions such as hydrogen bond, coordinate bond, van der Waals force, etc. Materials that can be useful.

In particular, according to the present invention, a polymer or oligomer which can be dissolved in a solvent in a temperature range higher than room temperature (25 ° C.) but solidifies at room temperature to form a gel reversibly, In addition to polymers and oligomers having a polar group such as an ether group or a hydroxyl group in the molecule, a group of substances known as oil gelling agents are preferably used as reversible gelling agents in non-aqueous electrolyte systems.

Examples of the polymer having a polar group such as an ether group or a hydroxyl group in the molecule include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, and polyvinyl alcohol.

As described in "Polymer Processing", Vol. 45, No. 1, pp. 21-26 (1996), an oil gelling agent can be used to add a small amount of oil to oils so that the entire oil is added. Various drugs that can be set in a jelly form are already known.

In the present invention, any known oil gelling agent can be used as the reversible gelling agent without any particular limitation. Preferred specific examples For example, 12
-Hydroxystearic acid, N-lauroyl-L-glutamic acid-α, γ-bis-n-butylamide, 1,2,3,4
-Dibenzylidene-D-sorbitol, tribenzylidene sorbitol, bis (p-methylbenzylidene) sorbitol, aluminum dialkylphosphate, 2,3-bis-n-hexadecyloxyanthracene, trialkyl-
Cis-1,3,5-cyclohexanetricarboxamide,

[0020]

Embedded image

Cholesterol derivatives such as

[0022]

Embedded image

A cyclohexanediamino derivative such as

[0024]

Embedded image

Allophanoic acid ester derivatives and the like can be mentioned.

In the present invention, the electrolyte salt may be a hydrogen ion, an ion of an alkali metal such as lithium, sodium or potassium, an ion of an alkaline earth metal such as calcium or strontium, or a tertiary or quaternary ammonium ion. As ingredients, hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid,
Anionic components include inorganic acids such as tetrafluoroboric acid, hydrofluoric acid, hexafluorophosphoric acid, and perchloric acid; and organic acids such as organic carboxylic acids, fluorine-substituted organic carboxylic acids, organic sulfonic acids, and fluorine-substituted organic sulfonic acids. Can be used. Among these, an electrolyte salt containing an alkali metal ion as a cation component is particularly preferably used.

Specific examples of such an electrolyte salt having an alkali metal ion as a cation component include, for example, alkali metal perchlorates such as lithium perchlorate, sodium perchlorate and potassium perchlorate, and tetrafluoroboric acid. Lithium, sodium tetrafluoroborate, alkali metal tetrafluoroborate such as potassium tetrafluoroborate, lithium hexafluorophosphate, alkali metal hexafluorophosphate such as potassium hexafluorophosphate,
Examples thereof include alkali metal trifluoroacetates such as lithium trifluoroacetate and alkali metal trifluoromethanesulfonates such as lithium trifluoromethanesulfonate.

In the present invention, the non-aqueous (organic) solvent for the electrolyte salt is appropriately selected without particular limitation as long as it dissolves the electrolyte salt to be used. Examples include cyclic esters such as carbonate, propylene carbonate, butylene carbonate and γ-butyrolactone, ethers such as tetrahydrofuran and dimethoxyethane, and chain esters such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate. These can be used alone or as a mixture of two or more.

Effective reversible sol dissolved in non-aqueous electrolyte
In order to form a gel electrolyte composition, the amount of the reversible gelling agent is determined not only by itself, but also depending on the electrolyte salt and solvent used, but usually the obtained reversible sol-gel It is in the range of 0.1 to 20% by weight of the solid electrolyte composition, preferably 1 to 10% by weight. Depending on the gelling agent used, even at a blending amount in the range of 1 to 5% by weight,
Form a fully effective reversible sol-gel electrolyte composition.

The amount of the electrolyte salt in the non-aqueous electrolyte is also
It is appropriately determined according to the reversible gelling agent and the solvent to be used as well as the solvent itself, but is usually in the range of 1 to 20% by weight of the obtained reversible sol-gel electrolyte composition.

According to the present invention, an effective reversible sol-gel electrolyte composition can be formed by adding a small amount of a reversible gelling agent to a non-aqueous electrolyte as described above. Since the solid electrolyte obtained by gelling the reversible sol-gel electrolyte composition has a small amount of the reversible gelling agent, the decrease in conductivity is less than that of the original non-aqueous electrolyte, and Since the decrease in conductivity at low temperatures is small, the charge and discharge characteristics of the battery are also excellent.

Accordingly, in the present invention, the reversible sol-gel electrolyte composition is preferably obtained by adding the above-mentioned reversible gelling agent to a non-aqueous electrolyte comprising a non-aqueous solvent and an electrolyte salt dissolved therein. Is heated, for example, to a temperature of 40 ° C. or higher,
By stirring, a sol is formed reversibly, and when the sol is cooled to room temperature (25 ° C.), it has a characteristic that a gel can be formed reversibly.

In the present invention, the porous membrane having pores for a separator for an electrochemical element is formed by dissolving the electrolyte salt in an electrolytic solution to form a reversible sol-gel electrolyte composition. Is carried on a porous membrane having pores.

The porous membrane used in the present invention is particularly limited as long as it does not dissolve in a non-aqueous solvent for dissolving the electrolyte salt, does not have electron conductivity, and is electrochemically stable. Without being used, various things are used,
A porous film made of a polyolefin resin such as polyethylene or polypropylene, or a fluororesin such as polytetrafluoroethylene resin is preferably used. Further, a porous film made of polyimide resin or glass fiber is also used.

The porous film has a thickness of 10 to 20.
It is preferably in the range of 0 μm. When the film thickness is smaller than 10 μm, the film strength is insufficient, and when incorporated in an electrochemical element as a separator, an internal short circuit may occur. On the other hand, when the film thickness exceeds 200 μm, the electrode The distance is too large, which unnecessarily increases the internal resistance of the electrochemical device. In addition, the porous membrane has a thickness of 100
It is desirable to have a piercing strength of gf or more. If the piercing strength is too low, when incorporated into an electrochemical element, it cannot withstand the surface pressure of the electrode and may cause an internal short circuit.

The average pore diameter of the pores of the porous membrane is 0.0
A range of 1 to 10 μm is preferred. If the average pore size of the pores is too large, the electrode material may destroy the gel electrolyte portion and cause an internal short circuit. On the other hand, when the average pore diameter of the pores is too small, the separator obtained by filling such a porous membrane with the electrolyte does not have sufficient ionic conductivity, so that the obtained electrochemical element has sufficient characteristics. Not.

Further, it is desirable that the porous film has a high porosity. However, in order to satisfy the above-mentioned conditions, the range is usually in the range of 25 to 90%. If the porosity is too high, there is no problem in terms of ionic conductivity, but the membrane strength is reduced and the pore diameter is increased, resulting in the above-described problem. On the other hand, when the porosity is too low, as in the case where the average pore diameter of the pores is too small, the obtained separator does not have sufficient ionic conductivity, so that the obtained electrochemical element has sufficient characteristics. Not.

The gelling agent is supported on the porous membrane without any particular limitation. For example, a solution in which the gelling agent is dissolved in an appropriate solvent is prepared, and this gelling agent solution is prepared. After impregnating the porous membrane, the solvent may be removed from the porous membrane. Since the gelling agent solution forms a sol or gel depending on the solvent, the gelling agent, the temperature, etc.,
In the case of a sol, the porous membrane may be impregnated as it is, and in the case of a gel, it may be formed into a sol and then impregnated in the porous membrane. Further, the gelling agent solution may be applied to the surface of the porous membrane by means such as coating or spraying. As described above, if the solvent is removed after the gelling agent solution is supported on the porous membrane, the gelling agent can be supported on the porous membrane.

After the porous membrane is impregnated with the gelling agent solution, the solvent may be removed from the porous membrane by generally heating and drying the porous membrane. May be used.

As described above, the porous membrane having pores for the separator for an electrochemical element used in the present invention is:
It carries a reversible gelling agent, thus forming a work-in-progress of an electrochemical element by arranging a pair of electrodes facing each other via such a porous membrane, and forming the electrolyte salt and the electrolyte salt. After impregnating the in-process product with the solvent comprising the solvent of the above, and dissolving the reversible gelling agent in the electrolyte to form a sol of the reversible sol-gel electrolyte composition, By gelling, the pores of the porous membrane are filled with the solid electrolyte composed of the gel of the reversible sol-gel electrolyte composition, and thus a pair of electrodes are disposed opposite each other via a separator. Thus, an electrochemical element in which the separator is filled with the solid electrolyte in the pores can be obtained.

More specifically, for example, a porous membrane for the separator is laminated with an electrode or combined by winding together, and a pair of electrodes are opposed to each other via the porous membrane. Arrange, this, for example, placed in the battery outer body,
In other words, after assembling the work-in-progress, an electrolytic solution is injected into the outer package, and the reversible gelling agent supported on the porous membrane is dissolved in the electrolytic solution by appropriate means such as heating, and thus, the outer package is formed. A reversible sol-gel electrolyte composition is prepared therein, and then cooled to gel the reversible sol-gel electrolyte composition, whereby a porous membrane having pores filled with a solid electrolyte is provided. Thus, an electrochemical device having an electrode disposed via a separator made of is easily obtained with good productivity.

In addition, according to the electrochemical device obtained in this manner, since the electrolyte contained therein is solid, there is no danger of liquid leakage. Electrolyte is also impregnated into the voids of the electrodes and forms a solid electrolyte after gelation, so that sufficient contact between the electrolyte and the electrodes can be ensured, and as a result, the internal resistance is small. Give an electrochemical device.

[0043]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited by these examples.

Example 1 (Preparation of positive electrode sheet) Lithium cobaltate (LiCoO
₂ , average particle size 15 μm), graphite powder and polyvinylidene fluoride resin were mixed at a weight ratio of 85: 10: 5, and the mixture was added to N-methyl-2-pyrrolidone, and stirred to obtain a solid content concentration of 15 wt. % Slurry was prepared. Using a coating machine, apply this slurry to the surface of a 20 μm-thick aluminum foil (current collector) to a thickness of 200 μm, dry at 80 ° C. for 1 hour, and further apply the slurry to the back of the aluminum foil. Was applied to a thickness of 20 μm and dried. Then
The thus treated aluminum foil was heated at 120 ° C. for 2 hours, dried and passed through a roll press to a thickness of 200 mm.
A μm positive electrode sheet was produced.

(Preparation of Negative Electrode Sheet) Graphite powder and polyvinylidene fluoride resin were mixed at a weight ratio of 95: 5, and this was charged into N-methyl-2-pyrrolidone, and stirred to obtain a solid content of 15% by weight. % Slurry was prepared. Using a coating machine, apply this slurry to a surface of a 20 μm thick copper foil (current collector) to a thickness of 200 μm, heat at 80 ° C. for 1 hour, dry, and further apply The slurry was applied to a thickness of 200 μm, heated at 80 ° C. for 1 hour, and dried. Thereafter, the thus treated copper foil was heated at 120 ° C. for 2 hours, dried, and then passed through a roll press to produce a 200 μm-thick negative electrode sheet.

(Preparation of porous membrane supporting gelling agent)
5% by weight of the gelling agent represented by the formula (5) is dissolved in ethanol at 70 ° C. to form a solution.
At ultra-high molecular weight polyethylene resin porous film (film thickness 40μ)
m, porosity 81%, average pore size 1.5 μm)
After drying at 60 ° C. for 10 minutes, the gelling agent was added at 0.7 mg / cm.
^A porous membrane supported at a ratio of ² was obtained.

(Preparation of Electrolyte Solution) Lithium hexafluorophosphate (LiPF ₆ ) as an electrolyte was dissolved in a solvent composed of a mixture of ethylene carbonate and propylene carbonate at a weight ratio of 1: 1 so as to have a concentration of 1 mol / L. And a non-aqueous electrolyte.

(Production of Battery) The above positive electrode sheet was 58 m wide.
m, cut into dimensions of 550 mm long, and the negative electrode is 59 m wide
m, and cut to a length of 600 mm, and a lead was attached to each current collector. These electrode sheets and width 60mm
The porous membrane supporting the gelling agent cut into a layer is alternately laminated, and this is wound into a coil shape so that the porous membrane is positioned on the outermost side to form a cylinder, and the outermost porous membrane is formed. Was fixed on the inner porous film with an adhesive tape to prepare a work-in-progress of an electrochemical element. The work-in-progress was inserted into an aluminum battery can, and the work-in-progress was separately inserted into a battery bag made of a polyethylene terephthalate resin film on which aluminum was deposited.

Next, the non-aqueous electrolyte was poured into the battery can and the battery bag, respectively, the mouth of the battery can was covered, and the opening of the battery bag was heat-sealed and sealed for 2 hours. After heating to 85 ° C, cool to room temperature,
Lithium ion secondary batteries were obtained as can batteries and bag batteries, respectively.

Example 2 10% by weight of the gelling agent represented by the above formula (5) was dissolved in γ-butyrolactone at 80 ° C. to form a solution, and the ultra-high molecular weight polyethylene resin porous membrane was formed at 80 ° C. (Film thickness: 40 μm, porosity: 81%, average pore size: 1.5 μm), and then cooled to room temperature to obtain a porous membrane supporting γ-butyrolactone gel. Next, this porous membrane was immersed in ethanol at room temperature for 2 minutes, and the gelling agent was precipitated by replacing γ-butyrolactone with ethanol, and was carried on the porous membrane. Next, the porous membrane thus treated is heated at 60 ° C. for 10 minutes to evaporate ethanol to obtain a porous membrane having a gelling agent loaded thereon at a rate of 1.0 mg / cm ^2. Was.

A lithium ion secondary battery was obtained as a can battery and a bag battery, respectively, in the same manner as in Example 1 except that a porous film carrying a gelling agent was prepared in this manner.

Example 3 12- as a gelling agent in γ-butyrolactone at 80 ° C.
Hydroxystearic acid (10% by weight) is dissolved to form a solution. In this solution, an ultra-high molecular weight polyethylene resin porous membrane (film thickness: 40 μm, porosity: 81%, average pore diameter: 1.5)
μm), and cooled to room temperature to obtain a porous membrane supporting γ-butyrolactone gel. Next, this porous membrane was immersed in ethanol at room temperature for 2 minutes, and the gelling agent was precipitated by replacing γ-butyrolactone with ethanol, and was carried on the porous membrane. Next, the porous membrane thus treated is heated at 60 ° C. for 10 minutes,
Ethanol is evaporated and the gelling agent is 1.2mg / c
A porous membrane supported at a rate of m ² was obtained.

A lithium ion secondary battery was obtained as a can battery and a bag battery, respectively, in the same manner as in Example 1 except that the porous membrane supporting the gelling agent was prepared in this manner.

Example 4 A polyethylene resin porous membrane (film thickness 27 μm, porosity 4
5%) and a porous membrane having a gelling agent supported at a rate of 0.4 mg / cm ² was prepared in the same manner as in Example 1.
Lithium ion secondary batteries were obtained as can batteries and bag batteries, respectively.

Example 5 Example 1 was repeated except that a porous film was prepared by supporting a gelling agent at a rate of 0.9 mg / cm ^{2 on} a polypropylene resin nonwoven fabric (film thickness 150 μm, porosity 50%). In the same manner as in the above, lithium ion secondary batteries were obtained as can batteries and bag batteries, respectively.

COMPARATIVE EXAMPLE 1 In Example 1, a porous film of ultra-high molecular weight polyethylene resin (film thickness of 40) was used in place of the porous film supporting the gelling agent.
μm, porosity 81%, average pore diameter 1.5 μm) in the same manner as in Example 1, except that lithium ion secondary batteries were obtained as can batteries and bag batteries, respectively.

Comparative Example 2 Example 1 was repeated except that a porous polyethylene resin membrane (thickness: 27 μm, porosity: 45%) was used in place of the porous membrane supporting the gelling agent. In the same manner as in the above, lithium ion secondary batteries were obtained as can batteries and bag batteries, respectively.

Comparative Example 3 In Example 1, a nonwoven fabric made of a polypropylene resin (150 μm in film thickness) was used instead of the porous film carrying the gelling agent.
A lithium ion secondary battery was obtained as a can battery and a bag battery, respectively, in the same manner as in Example 1 except that porosity was 45%.

Comparative Example 4 Lithium perchlorate (LiClO ₄ ) was dissolved in propylene carbonate at a concentration of 1 mol / L to obtain a non-aqueous electrolyte.
To this was added 30% by weight of polyethylene oxide (manufactured by Aldrich, average molecular weight 900000), heated and melted, then cast and cooled on a stainless steel plate to form a sheet, which was heated at 60 ° C. in vacuum for 2 hours. After drying, a sheet-like gel electrolyte was obtained.

The gel electrolyte sheet obtained in this manner was replaced with a porous membrane supporting a gelling agent, and alternately laminated with an electrode sheet in the same manner as in Example 1. And wound into a cylinder. The outermost sheet electrolyte was fixed on the inner sheet electrolyte with an adhesive tape to produce an electrochemical element.
This electrochemical element was inserted into a battery can made of aluminum, and the above-mentioned in-process product was separately inserted into a battery bag of a film made of polyethylene terephthalate resin on which aluminum was vapor-deposited, thereby obtaining lithium ion secondary batteries.

The internal resistance of each of the batteries thus obtained was measured, and a hole having a diameter of 1 mm was made in the outer package, and the hole was turned downward, left for 30 minutes, and the weight before and after the storage was measured. Then, the presence or absence of leakage of the electrolyte (liquid) was examined. Table 1 shows the results. The internal resistance of the battery was measured at a frequency of 10 kHz using an LCR meter (KC-546 manufactured by Kokuyo Electric Co., Ltd.).

From the results shown in Table 1, in the battery according to the method of the present invention, the internal resistance of the battery is small and there is no liquid leakage.

[0063]

[Table 1]

[0064]

According to the method of the present invention, as described above,
A porous membrane for an electrochemical element separator supporting a reversible gelling agent is prepared, and a pair of electrodes are disposed opposite to each other to form a work-in-progress of the electrochemical element. And the electrolyte comprising a solvent for the electrolyte salt was impregnated into the work-in-process, and the reversible gelling agent was dissolved in the electrolyte to form a sol of a reversible sol-gel electrolyte composition. Thereafter, the sol is gelled, and the pores of the porous membrane are filled with a solid electrolyte composed of a gel of the reversible sol-gel electrolyte composition, thus obtaining an electrochemical element. An electrochemical device in which the solid electrolyte is filled in the pores of the membrane can be easily manufactured with high productivity. Such an electrochemical device can be suitably used, for example, for manufacturing batteries, capacitors, capacitors, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 10/04 H01G 9/02 311 (72) Inventor Keisuke Kii 1-1-1 Shimohozumi, Ibaraki-shi, Osaka No. 2 Nitto Denko Corporation F term (reference) 5H028 AA06 BB03 BB15 CC08 EE06 5H029 AJ14 AK03 AL06 AM16 CJ02 CJ23 CJ28 DJ13 EJ12

Claims (5)

[Claims] 1. A pore for a separator for an electrochemical device, comprising a reversible gelling agent capable of forming a reversible sol-gel electrolyte composition together with an electrolyte salt and a solvent for the electrolyte salt. Prepare a porous membrane having a pair of electrodes facing each other to form a work-in-progress of an electrochemical element, and deposit an electrolytic solution comprising the electrolyte salt and a solvent for the electrolyte salt on the work-in-process. After the product is impregnated, the reversible gelling agent is dissolved in an electrolytic solution to form a sol of the reversible sol-gel electrolyte composition, the sol is gelled, and thus the porous membrane A method for producing an electrochemical device, characterized by filling a pore of the above with a solid electrolyte comprising a gel of the reversible sol-gel electrolyte composition. 2. The production of an electrochemical device according to claim 1, wherein the reversible sol-gel electrolyte composition changes from a gel to a sol by heating, and changes from a sol to a gel by cooling. Method. 3. The method for producing an electrochemical device according to claim 1, wherein the reversible gelling agent is an oil gelling agent. 4. The method according to claim 1, wherein the electrochemical device is a battery device. 5. The method according to claim 1, wherein the electrochemical device is a capacitor device or a capacitor device.