JP2000294288A - Lithium secondary battery and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a newly structured lithium secondary battery improved so that a dendrite can be completely prevented from being deposited, alignment is facilitated when stacked and battery cells can be excellently packaged for instance. SOLUTION: In this lithium secondary battery, a positive electrode and/or a negative electrode is composed of at least a collector and an active material layer adhered onto it by a polymer while holding an electrolyte, the polymer is induced from a gel forming monomer, and the positive electrode and the negative electrode are flatly stacked with intervention of an electrolyte layer formed by the electrolyte held by the polymer induced from the gel forming monomer. The collectors on the positive electrode side and on the negative electrode side have the almost same sizes, an insulating spacer is disposed on the peripheral rim part of the positive collector and the active material is formed inside the insulating spacer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lithium secondary battery and a method for manufacturing the same, and more particularly, to a lithium secondary battery having a novel structure and an industrially advantageous method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a positive electrode and / or a negative electrode has at least a current collector and an active material layer fixed on the current collector with a polymer and holding an electrolytic solution.
A lithium secondary battery in which the above-described polymer is derived from a gel-forming monomer, and the above-described positive electrode and negative electrode are laminated in a flat plate via an electrolyte layer in which an electrolyte is held by the polymer derived from the gel-forming monomer Is known.

[0003] In a lithium secondary battery,
The size of the positive electrode is made smaller than that of the negative electrode in order to prevent the occurrence of dendrite.However, it is difficult to handle electrodes having different sizes in this way, for example, in positioning during stacking, for example, in packaging. Accompanied by

[0004] As a method of manufacturing the above-mentioned lithium secondary battery, for example, a method for preparing an electrode containing an active material, an electrolytic solution, and a gel-forming monomer is applied on a current collector, and then the gel-forming monomer is coated. To form a positive electrode and a negative electrode, and then applying a gel electrolyte layer paint containing an electrolyte solution and a gel-forming monomer on the positive electrode or the negative electrode, and then polymerizing the gel-forming monomer. Is known (JP-A-5-41247).

However, in the case of the above method, the viscosity of the coating material for electrode preparation is limited due to the necessity of smooth coating, and the capacity of the battery is sufficiently increased by increasing the amount of active material in the electrode. There is a problem that you can not do. In particular, the above problem is remarkable in the case of an industrial process that requires continuous coating.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to completely prevent dendrite precipitation and facilitate alignment during lamination. An object of the present invention is to provide a lithium secondary battery having a novel structure improved so that the packaging of a battery element can be performed well. Another object of the present invention is to
It is still another object of the present invention to provide a method for manufacturing a lithium secondary battery improved so that the concentration of an active material in an electrode can be increased.

[0007]

As a result of various studies, the present inventor has found that (1) an insulative spacer is arranged on the periphery of a positive electrode current collector having substantially the same dimensions as the negative electrode current collector. By adopting a structure in which electrodes are formed inside,
(2) It has been found that the above object can be easily achieved by using the compression molding means, and the present invention has been completed.

That is, a first gist of the present invention is that a positive electrode and / or a negative electrode is composed of at least a current collector and an active material layer fixed on the current collector with a polymer and holding an electrolytic solution. A lithium secondary battery in which the above-described polymer is derived from a gel-forming monomer, and the above-described positive electrode and negative electrode are laminated in a flat plate via an electrolyte layer in which an electrolyte is held by the polymer derived from the gel-forming monomer The current collector on the positive electrode side and the current collector on the negative electrode side have substantially the same dimensions, and an insulating spacer is arranged on a peripheral portion on the positive electrode current collector and inside the insulating spacer. The present invention resides in a lithium secondary battery in which the above active material layer is formed.

A second gist of the present invention is that a positive electrode and / or a negative electrode is composed of at least a current collector and an active material layer fixed on the current collector with a polymer and holding an electrolytic solution. A lithium secondary battery in which the above-described positive electrode and negative electrode are laminated in a plate shape through an electrolyte layer in which the polymer is derived from a gel-forming monomer, and an electrolyte is held by the polymer derived from the gel-forming monomer. A method for manufacturing a battery, comprising: disposing an insulating spacer at a peripheral portion of a positive electrode current collector, and then forming an electrode preparation mixture containing at least an active material, an electrolytic solution, and a gel-forming monomer inside the insulating spacer. Compression molding process (A)
2. The method for producing a secondary battery according to claim 1, comprising a step (B) of polymerizing the gel-forming monomer.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, for convenience of explanation, a method of manufacturing a secondary battery according to the present invention will be described. The production method of the present invention comprises a positive electrode and / or a negative electrode comprising at least a current collector and an active material layer fixed on the current collector with a polymer and holding an electrolytic solution. The present invention is applied to a lithium secondary battery in which the above-described positive electrode and negative electrode are laminated in a plate shape via an electrolyte layer in which an electrolyte is retained by a polymer derived from a monomer and derived from a gel-forming monomer. In addition, any one of the above-described electrodes (usually, a negative electrode) can be formed of a metal itself such as a lithium foil.

As the current collector, a metal foil such as aluminum or copper or a wire net is usually used, and its thickness is appropriately selected, but it is usually 1 to 50 μm, preferably 5 to 30 μm. The current collector is preferably used after being subjected to a roughening treatment in advance in order to increase the adhesive strength with the active material layer fixed thereon. Examples of the surface roughening method include a mechanical polishing method, an electrolytic polishing method, and a chemical polishing method. In the mechanical polishing method, a polishing cloth paper having abrasive particles fixed thereon, a grindstone, an emery buff, a wire brush provided with a steel wire, or the like is used.

Further, the current collector may be provided with an adhesive layer in order to increase the adhesive strength with the active material layer. The adhesive layer is usually composed of a mixture containing an adhesive compound and a binder resin, and as such a mixture, for example,
A mixture described in JP-B-7-70328 can be used. The thickness of the adhesive layer is usually 0.05 to 1
0 μm, preferably 0.1 to 1 μm.

As the positive electrode active material composed of an inorganic compound,
Transition metal oxides, composite oxides of lithium and transition metals,
Transition metal sulfide and the like. As the above transition metal, Fe, Co, Ni, Mn and the like are used. Specific examples of the inorganic compound used for the positive electrode active material include Mn
Transition metal oxides such as O, V ₂ O ₅ , V ₆ O ₁₃ and TiO ₂ ; composite oxides of lithium and transition metals such as lithium nickelate, lithium cobaltate and lithium manganate; TiS
2, transition metal sulfides such as FeS and MoS ₂ . As a positive electrode active material composed of an organic compound, for example,
Examples thereof include polyaniline, polypyrrole, polyacene, disulfide-based compounds, polysulfide-based compounds, and N-fluoropyridinium salts. The particle size of the positive electrode active material is
Usually, it is 1 to 30 μm, preferably 1 to 10 μm.

Examples of the negative electrode active material include carbon-based active materials such as graphite and coke. Examples of the negative electrode active material include oxides and sulfates of silicon, tin, zinc, manganese, iron, nickel and the like, metallic lithium, Li-Al, Li
Lithium alloys such as -Bi-Cd and Li-Sn-Cd, lithium transition metal nitrides, silicon and the like can also be used. The particle size of the negative electrode active material is usually 1 to 50 μm, preferably 5 to 2 μm.
0 μm.

As the lithium salt (supporting electrolyte) which is a component of the electrolytic solution, LiPF ₆ or LiClO ₄ is preferable. On the other hand, as a solvent that is another component of the electrolytic solution, one or more selected from cyclic carbonates such as ethylene carbonate and propylene carbonate, and non-cyclic carbonates such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate are used. Are preferred. In order to enhance the stability, performance and life of the battery, for example, trifluoropropylene carbonate, vinylene carbonate, catechol carbonate,
1,6-Dioxaspiro [4,4] nonane
Additives such as -2,7-done and 12-crown-4-ether may be added.

As the gel-forming monomer (precursor monomer of the polymer), acrylic acid, methyl acrylate, ethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, ethoxyethyl acrylate, methoxyethyl acrylate, ethoxyethoxyethyl acrylate , Polyethylene glycol monoacrylate,
Ethoxyethyl methacrylate, methoxyethyl methacrylate, ethoxyethoxyethyl methacrylate, polyethylene glycol monomethacrylate, N, N diethylaminoethyl acrylate, N, N dimethylaminoethyl acrylate, glycidyl acrylate, allyl acrylate, acrylonitrile, N-vinylpyrrolidone, diethylene glycol diacrylate, Reactive unsaturated group-containing monomers such as triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and polyethylene glycol dimethacrylate. The “gel-forming monomer” in the present invention is not limited to only the compound corresponding to the minimum repeating unit constituting the polymer, but also includes other compounds that form the polymer by polymerization (for example, dimer).

As a method for polymerizing the above-mentioned gel-forming monomer, there are mentioned heat polymerization and ultraviolet irradiation polymerization as described later. Therefore, the above-mentioned gel-forming monomer is usually used together with various polymerization initiators according to the above-mentioned polymerization method.

Examples of the thermal polymerization initiator include 1,1-di (tert-butylperoxy) -3,3,5-trimethylcyclohexane and 2,2-bis- [4,4-di (tert-butylperoxy). Cyclohexyl) propane], 1,
1-di (tert-butylperoxy) -cyclohexane, tert-butylperoxy-3,5,5-trimethylhexanate, tert-butylperoxy-2
-Ethyl hexanonate, dibenzoyl peroxide and the like. Examples of the ultraviolet polymerization initiator include benzoin, benzyl, acetophenone, benzophenone, Michler's ketone, biacetyl, benzoyl peroxide and the like.

If necessary, the electrode may contain an additive exhibiting various functions such as a conductive material and a reinforcing material. The conductive material is not particularly limited as long as it is capable of imparting conductivity by being mixed in an appropriate amount with the active material, and usually includes acetylene black, carbon black, carbon powder such as graphite, and various metal fibers and foils. . In addition, to increase the stability and life of the battery, trifluoropropylene carbonate, vinylene carbonate,
Catechol carbonate, 1,6-Dioxaspir
o [4,4] nonane-2,7-dione, 12
-Crown-4-ether and the like can be used. Further, as a reinforcing material, various inorganic and organic spherical, plate-like, rod-like,
Fillers such as fibrous can be used.

Further, a binder can be contained in the electrode to improve its mechanical strength. Examples of such a binder include various resins in addition to inorganic compounds such as silicate and glass. As the binder resin, for example, polyethylene, polypropylene, alkane-based polymers such as poly-1,1-dimethylethylene, polybutadiene, unsaturated polymers such as polyisoprene,
Polymers having a ring such as polystyrene, polymethylstyrene, polyvinylpyridine, poly-N-vinylpyrrolidone, polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, polymethyl acrylate,
Acrylic polymers such as polyethyl acrylate, polyacrylic acid, polymethacrylic acid, and polyacrylamide; fluorine resins such as polyvinyl fluoride, polyvinylidene fluoride, and polytetrafluoroethylene; and CN groups such as polyacrylonitrile and polyvinylidene cyanide Containing polymer,
Examples thereof include polyvinyl alcohol-based polymers such as polyvinyl acetate and polyvinyl alcohol, halogen-containing polymers such as polyvinyl chloride and polyvinylidene chloride, and conductive polymers such as polyaniline. The weight average molecular weight of these resins is usually from 1,000 to 3,000,000, preferably from 10,000 to 500,000.

The positive electrode and / or the negative electrode in the present invention is basically the same as a conventional lithium secondary battery, and is formed by fixing at least a current collector and a polymer thereon and holding an electrolyte. And an active material layer, wherein the polymer is derived from a gel-forming monomer.

A feature of the manufacturing method of the present invention lies in a step of manufacturing an electrode, in which an insulating spacer is arranged on a peripheral portion of a positive electrode current collector, and at least an active material, an electrolytic solution, and a gel are formed inside the insulating spacer. It comprises a step (A) of compression molding a mixture for electrode preparation containing a monomer and a step (B) of polymerizing the above gel-forming monomer.

In the present invention, the insulating spacer disposed on the peripheral portion of the positive electrode current collector is not particularly limited, but various resin films are preferably used. And
In the present invention, the current collectors on the positive electrode side and the negative electrode side have substantially the same dimensions (the size according to the vertical and horizontal dimensions), but the outer dimensions of the insulating spacers arranged on the peripheral edge of the positive electrode current collector From the viewpoint of completely preventing the precipitation of dendrite, the size is the same as the outer size of the conventional current collector on the positive electrode side, which is smaller than the current collector on the negative electrode side. The width of the insulating spacer is preferably smaller as the electrode area becomes larger, but the insulating spacer having an excessively small width is difficult to handle. Therefore, the width is usually 0.5 to 10 mm. Note that the insulating spacer has the same thickness as the active material layer fixed on the current collector.

In the compression molding step, specifically, a predetermined shape in which an insulating spacer is disposed on a peripheral portion of the lower mold (cavity) surface of the compression molding die (usually having substantially the same size as the cavity). ) Is placed, and the above-mentioned electrode preparation mixture as a molding material is put on the positive electrode current collector inside the insulating spacer, and the upper mold (core) is closed, followed by compression molding. Pressing and shaping is performed by a machine (press).

In the present invention, since a current collector having a desired shape is used as a current collector corresponding to a starting material in the production of a secondary battery, a punching process that wastes material is not required. At this time, only the positive electrode can be formed by the above method and the negative electrode can be composed of a metal having a predetermined shape. However, for the negative electrode, a mold having the same dimensions as the positive electrode production mold is used, and the compression molding is performed. Preferably, it is prepared by a method.

The mixture for preparing an electrode to be subjected to the above-mentioned compression molding is prepared from the above-mentioned material for forming an electrode, and may contain a viscosity modifier if necessary.

The ratio of the active material in the electrode preparation mixture is determined from the following viewpoints. That is, when the ratio of the active material is too large, the characteristics at a high rate tend to deteriorate, and compression molding tends to be difficult. On the other hand, if the proportion of the active material is too small, a secondary battery with a sufficiently increased capacity cannot be obtained. By the way, in the present invention, a coating step is not necessary for manufacturing an electrode, and therefore, the degree of freedom of the viscosity of the electrode preparation mixture is high. Therefore,
By increasing the active material content in the electrode preparation mixture, in other words, by increasing the ratio of the active material in the active material layer that is a component of the electrode, it is possible to easily improve the capacity of the secondary battery. I can do it. In the present invention, the lower limit of the proportion of the active material in the electrode preparation mixture is usually 20% by weight, preferably 40% by weight, more preferably 60% by weight, and particularly preferably 70% by weight. It is usually 90% by weight, preferably 80% by weight.

The proportion of the electrolytic solution in the mixture for preparing an electrode is determined from the following viewpoints. That is, when the proportion of the electrolytic solution is too large, the characteristics at a high rate tend to be deteriorated, and compression molding tends to be difficult. On the other hand, if the proportion of the electrolyte is too small, a secondary battery with a sufficiently increased capacity cannot be obtained. In the present invention,
The lower limit of the proportion of the electrolytic solution in the electrode preparation mixture is usually 1
It is 0% by weight, preferably 20% by weight, and the upper limit is usually 60% by weight, preferably 40% by weight. The proportion of the gel-forming monomer in the electrode preparation mixture is determined in the same manner as in the case of the above-mentioned electrolyte.

The ratio of the gel-forming monomer to the total amount of the electrolyte and the gel-forming monomer is determined from the following viewpoint. That is, if the proportion of the gel-forming monomer is too large, the properties at high rates tend to deteriorate,
If the amount is too small, the mechanical strength of the electrode tends to be insufficient. In the present invention, the lower limit of the proportion of the gel-forming monomer is usually 1% by weight, preferably 5% by weight, and the upper limit is usually 70% by weight, preferably 40% by weight, more preferably 20% by weight. It is said.

The proportions of other additives, polymerization initiators, additives such as conductive materials and reinforcing materials, binders and viscosity modifiers are usually not more than 20% by weight based on the total amount of the active material, the electrolyte and the gel-forming monomer. , Preferably 10% by weight or less,
More preferably, the content is 5% by weight or less. When the proportion of each of the above components exceeds 20% by weight, the proportions of the active material, the electrolytic solution, and the gel-forming monomer tend to be relatively low, which is not preferable. When each of the above components is used, the lower limit is usually 0.1% by weight based on the total amount of the active material, the electrolytic solution and the gel-forming monomer.

The mixture for preparing an electrode to be subjected to compression molding is as follows:
It must be adjusted to have flow properties that allow compression molding. Such viscosity adjustment is performed by selecting the particle size of the active material, the type of the electrolytic solution, and the amount used.
In addition, a solvent is used if necessary.

The thickness of the electrode-preparing mixture (in other words, the active material layer after the polymerization step described later) which is compression-molded on the current collector is determined from the following viewpoints. That is, when the active material layer is too thick, the rate characteristics tend to deteriorate, and when the active material layer is too thin, the capacity of the secondary battery as a whole becomes too low. In the present invention, the lower limit of the thickness of the active material layer is usually 1 μm, preferably 30 μm, and the upper limit is usually 1000 μm, preferably 200 μm.

The polymerization step itself of the gel-forming monomer can be carried out according to known heat polymerization or ultraviolet irradiation polymerization. Then, for example, a heat polymerization step can be performed simultaneously with the compression molding step, and after the compression molding step, a polymerization step can be performed on each of the positive electrode side and the negative electrode side. Further, a positive electrode and a negative electrode are formed by polymerization, and then a coating solution for a gel electrolyte layer containing an electrolytic solution and a gel-forming monomer is applied on the positive electrode or the negative electrode, and then the gel-forming monomer is polymerized. Methods can also be employed.

In the present invention, in the polymerization step of the gel-forming monomer, after the above-mentioned compression-molding step, a sheet carrying the electrolyte and the gel-forming monomer is interposed between the compression-molded electrode preparation mixtures. And heat treatment (thermal polymerization). According to such a method, each electrode electrode and the gel electrolyte layer are better integrated based on the wet state by the gel-forming monomer on the bonding surface, compared to the case where the positive electrode side and the negative electrode side are separately polymerized. As a result, a battery with low resistance is obtained.

As the sheet for supporting the electrolytic solution and the gel-forming monomer, various porous membranes and nonwoven fabrics used as battery separators can be used, and specifically, paper such as paper, Japanese paper, etc. And various types of natural and synthetic fibers, and commercially available filters used for separation and purification. The thickness of the sheet is usually 5
It is 200 μm, preferably 10 to 150 μm, more preferably 10 to 80 μm. In addition, the thermal polymerization of the gel-forming monomer in the above-mentioned laminated state is usually performed at 60 to 150 ° C.
Preferably, it is performed at a temperature of 60 to 100 ° C.

The battery element obtained as described above, in which the positive electrode and the negative electrode are laminated in a flat plate via a gel electrolyte layer in which an electrolyte is held in a polymer, is required to have, for example, external terminals and the like. After attaching and processing the components, a plurality of the components are stacked as necessary, and are housed in a case to form a secondary battery. As the case, a shape-variable case having flexibility, flexibility, flexibility, or the like may be used, or a rigid case may be used. Examples of the material of the case include plastic, a polymer film, a metal film, rubber, and a thin metal plate.

Next, the lithium secondary battery of the present invention will be described. The lithium secondary battery of the present invention is manufactured, for example, as described above. Its structural features are that the current collectors on the positive electrode side and the negative electrode side have substantially the same dimensions, and The present invention is characterized in that an insulating spacer is disposed on a peripheral portion on a body, and the above-mentioned active material layer is formed inside the insulating spacer.

In the lithium secondary battery having the above-described structure, when the battery element in which the positive electrode and the negative electrode are laminated in a plate shape with the electrolyte layer interposed therebetween, there is no uneven portion on the peripheral surface in the laminating direction. Is performed well. In addition, since the size of the positive electrode (the active material layer formed on the current collector) is smaller than that of the negative electrode, precipitation of dendrites is favorably prevented. Further, the strength is imparted to the entire lithium secondary battery by the insulating spacer, and the side surface of the active material layer is protected. Further, even if the side surface of the lithium secondary battery is subjected to histress and the end portion is deformed, the short circuit can be more completely prevented by the insulating spacer.

[0039]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In the following examples,
“Parts” means “parts by weight”. In addition, “Photomer 4050” and “Ph
Each of the “automer 4158” is a polyethylene oxide manufactured by Henkel and having an acrylic group bonded to the terminal via an ester group.

Example 1 <Preparation of mixture for electrode and mixture for formation of gel electrolyte layer> According to the composition shown in the following Tables 1 and 2, kneading and dispersion treatment was carried out in a kneader for 8 hours to prepare a coating for the positive electrode and a coating for the negative electrode. Prepared. Further, a composition for forming a gel electrolyte layer was prepared according to the composition shown in Table 3 below.

[0041]

(Table 1) (Positive electrode mixture) LiCoO ₂ (active material): 75.0 parts Acetylene black (conductive material): 6.0 parts Propylene carbonate (PC) (electrolyte): 8.0 parts Ethylene carbonate (EC) (Electrolytic solution): 8.0 parts LiClO ₄ (supporting electrolyte): 1.0 part “Photomer 4050”: 1.1 parts “Photomer 4158”: 1.1 parts Thermal crosslinking initiator (“Trignox21” manufactured by Ciba Geigy): 0 .5 copies

[0042]

(Table 2) (Mixture for negative electrode) Graphite (active material): 78.0 parts Propylene carbonate (PC) (electrolyte): 7.4 parts Ethylene carbonate (EC) (electrolyte): 7.4 parts LiClO ₄ ( Supporting electrolyte): 0.9 part "Photomer 4050": 1.8 parts "Photomer 4158": 1.8 parts Thermal crosslinking initiator ("Trignox21" manufactured by Ciba Geigy): 0.5 part

[0043]

(Table 3) (Mixture for forming gel electrolyte layer) Propylene carbonate (PC) (electrolyte): 44.0 parts Ethylene carbonate (EC) (electrolyte): 44.0 parts LiClO ₄ (supporting electrolyte): 5 parts “Photomer 4050”: 4.7 parts “Photomer 4158”: 2.3 parts Thermal crosslinking initiator (“Trignox21” manufactured by Ciba Geigy): 0.1 part

<Formation of Electrode and Formation of Electrolyte Layer> As a compression mold, the R of each corner of the lower mold and the upper mold is 1.5 mm,
A rectangular compression mold (length and width: about 10 cm) having a gap of 20 μm and a draft taper of 1.0 ° was used. As the current collector, a 20-μm-thick aluminum foil (positive electrode) and a copper foil (negative electrode) punched into a shape (R: 1.5 mm, vertical and horizontal: about 10 cm) following the shape in the mold are used. did. However, the positive electrode current collector was formed by processing a polypropylene film having a thickness of 80 μm into a window frame shape as an insulating spacer on a peripheral portion on the positive electrode current collector (vertical and horizontal lengths: about 10 cm, vertical and horizontal widths: About 1 cm) and heat-sealed.

First, the current collector is placed on the lower mold surface, and the mixture (sheet) for the electrodes for the positive electrode and the negative electrode is poured into the approximate center thereof, and the upper mold (core) is closed. Press molding was performed by a molding machine. At this time, in the case of the positive electrode current collector,
The dimensions of the sheet were adjusted to be small so that the sheet could be compression molded in the frame of the window frame-shaped polypropylene film. Then, after impregnating a non-woven fabric having a thickness of about 60 μ with the same shape as that of the current collector into the mixture for forming a gel electrolyte layer, the mixture is interposed between the positive electrode side and the negative electrode side obtained above at 90 ° C. At 10
Heated for a minute.

<Packaging Step> Next, the three battery elements obtained above are stacked so that the same poles are overlapped, and a positive electrode terminal and a negative electrode terminal are attached to each positive electrode terminal and each negative electrode terminal. It was sealed in a vacuum pack with a lid to produce a laminated lithium secondary battery.

[0047]

According to the lithium secondary battery of the present invention, the prevention of dendrite precipitation is more completely achieved, the packaging of the battery element is good, the overall strength is increased, the active material layer is protected, and the end portion is protected. Has a new structure improved to prevent short-circuiting due to deformation. Further, according to the method for producing a lithium secondary pond according to the present invention, the capacity, cycle characteristics,
A lithium secondary battery having excellent rate characteristics is provided. Moreover, the lithium secondary pond produced by the present invention has an excellent capacity, especially because of the high concentration of the active material in the electrode, and the current collector and the active material layer are firmly adhered to each other by compression molding, so that the adhesion is improved. Because it is good, the cycle characteristics are excellent. Further, according to the method for manufacturing a lithium secondary battery according to the present invention, the shape of the electrode is determined by molding, so that the material for forming the electrode can be used without waste, and the shape of the electrode can be arbitrarily selected. You can do it.

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Claims (4)

[Claims] 1. A positive electrode and / or a negative electrode comprising at least a current collector and an active material layer fixed on the current collector with a polymer and holding an electrolytic solution, and the polymer is formed from a gel-forming monomer. A lithium secondary battery in which the above-described positive electrode and negative electrode are laminated in a flat plate via an electrolyte layer in which an electrolyte is held by a polymer derived from a gel-forming monomer. And the current collector on the negative electrode side have substantially the same dimensions, and
A lithium secondary battery, wherein an insulating spacer is disposed at a peripheral portion on a positive electrode current collector, and the active material layer is formed inside the insulating spacer. 2. The method according to claim 1, wherein the positive electrode and / or the negative electrode comprises at least a current collector and an active material layer fixed on the current collector with a polymer and holding an electrolyte. Induced, and a method for producing a lithium secondary battery, wherein the positive electrode and the negative electrode are laminated in a flat plate via an electrolyte layer in which an electrolyte is retained in a polymer derived from a gel-forming monomer,
(A) compressing and molding an electrode preparation mixture containing at least an active material, an electrolytic solution, and a gel-forming monomer inside the insulating spacer after disposing the insulating spacer on the periphery of the positive electrode current collector; The method for producing a secondary battery according to claim 1, comprising a step (B) of polymerizing the gel-forming monomer. 3. An electrode preparation mixture containing at least an active material, an electrolytic solution and a gel-forming monomer on a current collector on the negative electrode side is compression-molded using a mold having the same dimensions as a mold for producing a positive electrode. The method according to claim 2, comprising a step and a step of polymerizing the gel-forming monomer. 4. An electrode preparation mixture is compression-molded on each of the positive electrode side and the negative electrode side current collectors, and an electrolytic solution and a gel-forming monomer are supported between the compression-molded electrode preparation mixtures. The method according to claim 2 or 3, further comprising a step of polymerizing the gel-forming monomer by heat-treating with the interposed sheet interposed.