JP5293539B2 - Electrode active material sheet with support and method for producing electrode for electrochemical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode active material sheet with a support which allows convenient and uniform formation of an electrode active material layer on a collector, especially a perforated collector having front-to-back through-holes such as a punching metal and an expanded metal, and a method for producing an electrode for an electrochemical element by using the same. <P>SOLUTION: The electrode active material sheet with a support comprises on the surface of a support an electrode active material layer made up of a binding agent A and an electrode active material, and an electro-conductive adhesive layer made up of a binding agent B and electro-conductive particles in this order. The method for producing an electrode for an electrochemical element comprises a process of sticking the electrode active material sheet with a support together to the collector, and a process of separating the support from the electrode active material sheet with a support which has been stuck together to the collector. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a secondary battery such as a lithium ion secondary battery or a lead-acid battery, a hybrid capacitor such as an electric double layer capacitor or a lithium-ion capacitor, or an electrode used for an electrochemical element such as a capacitor hybrid lead-acid battery (hereinafter referred to as the following). The present invention generally relates to an electrode active material layer used in the manufacture of an electrode and an electrochemical element electrode manufacturing method using the electrode active material layer.

Demand for electrochemical devices such as lithium ion secondary batteries, electric double layer capacitors, hybrid capacitors, and capacitor hybrid type lead-acid batteries by taking advantage of their small size, light weight, high energy density, and repeated charge / discharge characteristics. Is expanding rapidly. Lithium ion secondary batteries have a relatively high energy density and are therefore used in fields such as mobile phones and notebook personal computers. In addition, since the electric double layer capacitor can be rapidly charged and discharged, it is used as a memory backup compact power source for personal computers and the like. Furthermore, the electric double layer capacitor is expected to be applied as a large power source for electric vehicles. In addition, hybrid capacitors that make use of the advantages of lithium ion secondary batteries and electric double layer capacitors are attracting attention because of their high energy density and output density. With the expansion and development of applications, these electrochemical devices are required to be further improved such as lowering resistance, increasing capacity, and improving mechanical properties.

  The hybrid capacitor includes a polarizable electrode as a positive electrode and a nonpolarizable electrode as a negative electrode, and can increase an operating voltage and an energy density by using an organic electrolyte. In a hybrid capacitor, it has been proposed to use a material in which lithium ions are occluded in advance by a chemical method or an electrochemical method as a material that can occlude and desorb lithium ions (for example, Patent Documents 1 and 2). ).

  In cases where large cells such as automobile power supplies are targeted, as a method of supporting lithium on the negative electrode in advance, the positive electrode current collector and the negative electrode current collector each have a hole penetrating the front and back, and the negative electrode active material reversibly recharges lithium. An organic electrolyte battery has been proposed in which lithium from a negative electrode is supported by electrochemical contact with lithium arranged opposite to the negative electrode or the positive electrode (for example, see Patent Document 3). In Patent Document 3, holes that penetrate the front and back surfaces are provided in the current collector, and an electrode active material layer is formed on the front and back surfaces of the perforated current collector (hereinafter, the current collector having the through holes is referred to as “holes”). May be referred to as an "open current collector"). With such a configuration, the capacitance is improved, and lithium ions can move between the front and back of the electrode without being blocked by the current collector. Through this, lithium can be electrochemically supported not only on the negative electrode arranged in the vicinity of lithium but also on the negative electrode arranged away from lithium. In addition, since lithium ions can freely move between the electrodes through the through holes, charging and discharging proceed smoothly.

  The electrode active material layer is formed, for example, by applying and drying a slurry containing an electrode active material, a conductive material, and a binder on a current collector. In particular, for the purpose of simultaneously forming electrode active material layers on the front and back surfaces of the current collector, a pair of dies are arranged on both sides of the current collector transport path running in the vertical direction, A twin blade method has been proposed in which the blade is provided and the slurry discharged from the die is scraped off by the blade to control the coating thickness. However, in the case where the current collector is a perforated current collector having through holes, it is difficult to apply the slurry to a uniform thickness, and the thickness of the electrode active material layer and the electrode active material layer in the obtained electrode The amount of the electrode active material therein is not constant, and the electrode performance varies. This method also requires two dies to apply the slurry from both sides of the current collector, and also requires two sets of paint tanks, supply pumps, filters, piping, etc. Resulting in an increase in cost. Further, in order to control the coating thickness and the surface state of the electrode, it is necessary to strictly adjust the clearance between the two dies, the discharge amount of the slurry, the clearance of the die lip portion, and the like. Furthermore, when a perforated current collector such as punching metal or expanded metal is conveyed to a general horizontal coating machine such as a comma coater, the slurry is transferred to a rotating roller, and the slurry is collected uniformly. It was difficult to apply on an electric body.

  In addition, as a method for forming an electrode active material layer with a uniform thickness on a perforated current collector, for example, in Patent Document 4, an electrode material is supplied to a pair of press rolls using a quantitative feeder, and a press roll A method of simultaneously forming a sheet of electrode material and joining to the current collector by supplying a current collector therebetween is disclosed.

  In Patent Document 5, the slurry applied to the base material is brought into contact with the perforated current collector to be integrated, and then the slurry is dried, the base material is peeled off, and an electrode active material layer is formed on the current collector. A method has been proposed. In this method, since the slurry layer is dried in a state where the base material is laminated, the solvent of the slurry is difficult to evaporate uniformly. For this reason, in patent document 5, the porous base material is used as a base material, the solvent is evaporated uniformly, and the thickness of the electrode active material layer after drying is made uniform.

  In Patent Document 6, a sheet obtained by applying a paste containing an active material on a polyethylene terephthalate (PET) film and forming a sheet is then heated and pressure-bonded to both surfaces of an aluminum or copper expanded metal with a hot roll, and the electrolyte solution is not yet applied. An impregnated positive electrode or negative electrode material is formed.

JP-A-3-233860 JP-A-5-325965 International Publication No. 98/33227 JP 2007-5747 A JP 2008-41971 A JP-A-11-111337

  However, in the method described in Patent Document 4, when the electrode material is transferred from the press roll to the current collector, the electrode material may remain on the press roll. As a result, the amount of the electrode material transferred to the current collector is not constant, the thickness of the electrode active material layer becomes uneven, and the electrode characteristics may vary.

  Also in the method of Patent Document 5, when the porous substrate is peeled from the electrode active material layer after the slurry is dried, the electrode material remains on the porous substrate, which causes the same problem. In addition, there is a problem that the slurry viscosity and the pore diameter of the porous substrate are limited due to the application and drying of the slurry.

  Also in the method of Patent Document 6, when the active material formed into a sheet on the PET film is hot-rolled and heat-bonded on both surfaces of the expanded metal, the electrode material remains on the PET film, causing the same problem.

  Therefore, an object of the present invention is to provide a support that can easily and uniformly form an electrode active material layer on a current collector, particularly a perforated current collector having front and back through holes such as punching metal and expanded metal. An electrode active material sheet and an electrochemical element electrode manufacturing method using the same are provided.

  As a result of intensive studies to solve the above problems, the present inventor contains an electrode active material layer containing a binder and an electrode active material, a binder and conductive particles on the support surface. It was found that the electrode for an electrochemical element can be easily produced in a roll by using a support-attached electrode active material sheet having the conductive adhesive layers in this order.

  That is, this invention which solves the said subject contains the following matters as a summary.

(1) An electrode active material layer containing a binder A and an electrode active material, and a conductive adhesive layer containing a binder B and conductive particles on the surface of the support, Ri Na has sequentially, the conductive adhesive layer is formed by a slurry-like conductive adhesive compositions comprising a binder B and the conductive particles are dried, the electrode active material sheet with support.

(2) The support has a roughened surface, and the roughened surface faces the electrode active material layer,
The electrode active material sheet with a support according to (1), wherein the surface roughness Ra of the roughened surface is 0.1 to 5 μm.

(3) The electrode active material sheet with a support according to (1) or (2), wherein a surface of the support facing the electrode active material layer is subjected to a release treatment.

(4) The electrode active material sheet with a support according to (3), wherein a contact angle with water on a surface of the support that has been subjected to a release treatment is 80 ° to 120 °.

(5) A step of forming an electrode active material layer containing an electrode active material and a binder A on the surface of the support, and a binder B and conductive particles are included on the electrode active material layer. The manufacturing method of the electrode active material sheet | seat with a support body including the process of apply | coating the slurry-like conductive adhesive composition which consists of these, and forming a conductive adhesive layer by drying .

(6) A step of bonding the electrode active material sheet with a support according to any one of (1) to (4) to a current collector, and a support from the electrode active material sheet with a support bonded to the current collector The manufacturing method of the electrode for electrochemical elements including the process of isolate | separating a body.

(7) The method for producing an electrode for an electrochemical element according to (6), wherein the current collector is a current collector having a through hole.

(8) An electrochemical element comprising an electrode for an electrochemical element obtained by the production method according to (6) or (7).

(9) The electrochemical device according to (8), wherein the electrochemical device is a hybrid capacitor.

  According to the present invention, the electrode active material sheet before being laminated with the current collector can be produced alone and in a long roll. Moreover, an electrode active material layer can be efficiently formed on a current collector having through-holes or a roughened current collector by using this roll-shaped electrode active material sheet. In addition, by providing a conductive adhesive layer on the electrode active material layer, the transferability to the current collector is improved, and the contact with the current collector is also improved, and the internal resistance of the electric double layer capacitor or hybrid capacitor is improved. Can be reduced.

It is a figure showing the specific aspect of the manufacturing process of the electrode active material sheet with a support body of this invention. It is a figure showing the specific aspect of the manufacturing process of the electrode for electrochemical elements which uses the electrode active material sheet with a support body of this invention.

DESCRIPTION OF SYMBOLS 1 ... Support body 2 ... Current collector 3 ... Coating machine 4 ... Dryer 10, 12, 14 ... Unwinder 11, 13, 15 ... Winder 16 ... Laminator

<Electrode active material sheet with support>
The electrode active material sheet with a support of the present invention comprises an electrode active material layer containing a binder A and an electrode active material, a binder B and conductive particles on the support surface. The conductive adhesive layer is formed in this order.

(Support)
Examples of the material constituting the support used in the present invention include plastic film and paper. Moreover, you may use the film of the multilayered structure which accumulated the said film. Among these, from the viewpoint of versatility and handling, paper and thermoplastic resin film are preferable, thermoplastic resin film is more preferable, and among thermoplastic resin films, PET (polyethylene terephthalate) film, polyolefin film, PVA (polyvinyl chloride) Alcohol) film, PVB (polyvinyl butyral film), or PVC (polyvinyl chloride) film is preferred.

The support used in the present invention preferably has a roughened surface, and the roughened surface preferably faces the electrode active material layer. Since the support has a roughened surface and the roughened surface faces the electrode active material layer, it can be in close contact with the electrode active material layer due to the anchoring effect and can be rolled up. Become. Moreover, when manufacturing an electrode using an electrode active material sheet with a support, the support can be easily peeled from the electrode active material sheet with a support. The surface roughness Ra of the roughened surface of the support is preferably in the range of 0.1 to 5 μm, more preferably 0.2 to 3 μm, and still more preferably 0.2 to 1 μm. When the surface roughness Ra of the roughened surface of the support is within this range, the adhesion between the electrode active material layer and the support and the production of the electrode using the electrode active material layer with the support are performed. It is possible to achieve compatibility with the releasability of the support.
In addition, when the surface of the support is roughened, the surface area of the support increases, and when an electrode active material layer is formed by applying an aqueous slurry described later, the contact angle with water as the solvent is Decrease and coating becomes easy.
In accordance with JIS B0601-2001, the surface roughness Ra can be calculated from the equation shown below by drawing a roughness curve using, for example, a nanoscale hybrid microscope (VN-8010, manufactured by Keyence Corporation). . In the following formula, L is the measurement length, and x is the deviation from the average line to the measurement curve.

  The method for roughening the support surface is not particularly limited, a method for embossing the support surface; a method for sandblasting the support surface; a method for kneading a mat material into a material constituting the support; Examples thereof include a method of coating a layer containing a material on the support surface. Among these methods, a sandblasting method that can easily roughen the surface of the support is preferable. The roughening treatment of the support may be performed only on one side or on both sides.

  The support used in the present invention preferably has a release-treated surface. The method of mold release treatment is not particularly limited. For example, a method of applying a thermosetting resin such as an alkyd resin on a support and curing it; a method of applying a silicone resin on a support and curing it Method: It is preferable to use a method of coating a fluororesin on a support. In particular, a release treatment using a thermosetting resin capable of easily forming a homogeneous release treatment layer is preferable. Also, the moldability of the electrode active material layer and the support from the obtained electrode active material sheet with a support are preferred. From the viewpoint of balance of releasability, release treatment by coating and curing of alkyd resin is preferable.

  When the electrode active material layer is formed by applying an aqueous slurry, the contact angle with water on the release treatment surface of the support is preferably in the range of 80 ° to 120 °, more preferably in the range of 90 ° to 110 °. It is in. When the contact angle with water on the release treatment surface is too small, the slurry coatability is good, but it is difficult to peel the electrode active material layer formed after drying the slurry from the support. There is. On the other hand, when the contact angle is too large, it becomes easy to peel the electrode active material layer from the substrate, but the slurry is repelled on the surface of the support, making uniform coating difficult. Thus, although coatability and releasability are generally incompatible characteristics, by making the contact angle with water on the release treatment surface of the substrate within the above range, The releasability of the electrode active material layer is balanced, an electrode active material layer having a uniform thickness can be formed, and the electrode active material layer can be easily released.

  Although the thickness of a support body is not specifically limited, 10-200 micrometers is preferable, 20-150 micrometers is more preferable, 20-100 micrometers is especially preferable. When the thickness of the support is in the above range, the roll winding property and handling property of the electrode active material sheet with support are improved. The width is not particularly limited, but is preferably 100 to 1000 mm, more preferably 100 to 500 mm.

  Although the tensile strength of a support body is not specifically limited, 30-500 Mpa is suitable and 30-300 Mpa is more suitable. When the tensile strength of the support is within the above range, breakage during the production of the electrode active material sheet with the support can be prevented. The tensile strength of the support is measured according to JIS K7127.

  The support used in the present invention can be used repeatedly. By repeatedly using the support, the production cost of the electrode can be further reduced.

(Electrode active material layer)
The electrode active material layer used in the present invention contains a binder A and an electrode active material.

(Electrode active material)
The electrode active material used in the present invention is a substance that transfers electrons in an electrode for an electrochemical element. The electrode active material mainly includes an active material for a lithium ion secondary battery, an active material for an electric double layer capacitor, and an active material for a lithium ion capacitor.

Examples of the active material for a lithium ion secondary battery include a positive electrode and a negative electrode. As the electrode active material used for the positive electrode of a lithium ion secondary battery electrode, _{specifically, LiCoO 2, LiNiO 2, LiMnO} 2, LiMn 2 O 4, LiFePO 4, lithium-containing composite metal oxides such as LiFeVO _4; Transition metal sulfides such as TiS ₂ , TiS ₃ , and amorphous MoS ₃ ; Cu ₂ V ₂ O ₃ , amorphous V ₂ O · P ₂ O ₅ , MoO ₃ , V ₂ O ₅ , V ₆ O _13, etc. These transition metal oxides are exemplified. Furthermore, conductive polymers such as polyacetylene and poly-p-phenylene are listed. Preferred is a lithium-containing composite metal oxide.

  Specific examples of the electrode active material used for the negative electrode of the lithium ion secondary battery electrode include electrode active materials such as amorphous carbon, graphite, natural graphite, mesocarbon microbeads (MCMB), and pitch-based carbon fibers; polyacene And the like, and the like. Crystalline electrode active materials such as graphite, natural graphite, and mesocarbon microbeads (MCMB) are preferable.

  The shape of the electrode active material used for the electrode for a lithium ion secondary battery is preferably a granulated particle. When the shape of the particles is spherical, a higher density electrode can be formed during electrode molding.

  The volume average particle diameter of the electrode active material used for the electrode for a lithium ion secondary battery is usually 0.1 to 100 μm, preferably 1 to 50 μm, more preferably 5 to 20 μm for both the positive electrode and the negative electrode.

The tap density of the electrode active material used for the electrode for the lithium ion secondary battery is not particularly limited, but preferably 2 g / cm ³ or more for the positive electrode and 0.6 g / cm ³ or more for the negative electrode.

  As the electrode active material used for the electric double layer capacitor electrode, a carbon allotrope is usually used. Specific examples of the allotrope of carbon include activated carbon, polyacene, carbon whisker, and graphite, and these powders or fibers can be used. A preferred electrode active material is activated carbon, and specific examples include activated carbon made from phenol resin, rayon, acrylonitrile resin, pitch, coconut shell, and the like.

  The volume average particle diameter of the electrode active material used for the electric double layer capacitor electrode is usually 0.1 to 100 μm, preferably 1 to 50 μm, and more preferably 5 to 20 μm.

The specific surface area of the electrode active material used in the electrode for an electric double layer capacitor, 30 m @ 2 / g or more, and a preferably 500~5,000m ² / g, more preferably 1,000~3,000m ² / g . Since the density of the obtained electrode active material layer tends to decrease as the specific surface area of the electrode active material increases, an electrode active material layer having a desired density can be obtained by appropriately selecting the electrode active material.

Electrode active materials used for electrodes for lithium ion capacitors include positive electrodes and negative electrodes.
The electrode active material used for the positive electrode of the lithium ion capacitor electrode may be any material that can reversibly carry lithium ions and anions such as tetrafluoroborate. Specifically, an allotrope of carbon is usually used, and electrode active materials used in electric double layer capacitors can be widely used. When carbon allotropes are used in combination, two or more types of carbon allotropes having different average particle diameters or particle size distributions may be used in combination. Further, a polyacene organic semiconductor (PAS) which is a heat-treated product of an aromatic condensation polymer and has a polyacene skeleton structure having a hydrogen atom / carbon atom atomic ratio of 0.50 to 0.05 can also be used suitably. . Preferably, it is an electrode active material used for the electrode for electric double layer capacitors.

  The electrode active material used for the negative electrode of the electrode for lithium ion capacitors is a substance that can reversibly carry lithium ions. Specifically, electrode active materials used in the negative electrode of lithium ion secondary batteries can be widely used. Preferred examples include crystalline carbon materials such as graphite and non-graphitizable carbon, and polyacene-based materials (PAS) described as the positive electrode active material. These carbon materials and PAS are obtained by carbonizing a phenol resin or the like, activated as necessary, and then pulverized.

  The shape of the electrode active material used for the electrode for a lithium ion capacitor is preferably a granulated particle. When the shape of the particles is spherical, a higher density electrode can be formed during electrode molding.

  The volume average particle diameter of the electrode active material used for the lithium ion capacitor electrode is usually 0.1 to 100 μm, preferably 1 to 50 μm, more preferably 5 to 20 μm for both the positive electrode and the negative electrode. These electrode active materials can be used alone or in combination of two or more.

(Binder A)
The binder A used in the present invention is not particularly limited as long as it is a compound capable of binding the electrode active material and the conductive agent to each other. A suitable binder is a dispersion type binder having a property of being dispersed in a solvent. Examples of the dispersion-type binder include polymer compounds such as fluorine-based polymers, diene-based polymers, acrylate-based polymers, polyimides, polyamides, polyurethane-based polymers, and fluorine-based polymers and diene-based polymers. Alternatively, an acrylate polymer is preferable, and a diene polymer or an acrylate polymer is more preferable in that the withstand voltage can be increased and the energy density of the electrochemical element can be increased.

  The diene polymer is a homopolymer of a conjugated diene or a copolymer obtained by polymerizing a monomer mixture containing a conjugated diene, or a hydrogenated product thereof. The proportion of the conjugated diene in the monomer mixture is usually 40% by weight or more, preferably 50% by weight or more, more preferably 60% by weight or more. Specific examples of the diene polymer include conjugated diene homopolymers such as polybutadiene and polyisoprene; aromatic vinyl / conjugated diene copolymers such as carboxy-modified styrene / butadiene copolymer (SBR); Copolymers of styrene / butadiene / methacrylic acid copolymer and aromatic vinyl / conjugated diene / carboxylic acid group-containing monomers such as styrene / butadiene / itaconic acid copolymer; acrylonitrile / butadiene copolymer (NBR) And vinyl cyanide / conjugated diene copolymers such as hydrogenated SBR and hydrogenated NBR.

The acrylate polymer is represented by the general formula (1): CH ₂ = CR ¹ —COOR ² (wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group or a cycloalkyl group). It is a polymer containing the monomer unit derived from a compound. Specific examples of the compound represented by the general formula (1) include ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-amyl acrylate, Acrylates such as isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate; ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacryl Examples thereof include methacrylates such as t-butyl acid, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate and stearyl methacrylate. Among these, acrylate is preferable, and n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferable in that the strength of the obtained electrode can be improved. The ratio of the monomer unit derived from the compound represented by the general formula (1) in the acrylate polymer is usually 50% by weight or more, preferably 70% by weight or more. When an acrylate polymer in which the proportion of the monomer unit derived from the compound represented by the general formula (1) is within the above range is used, the heat resistance is high and the internal resistance of the obtained electrode for an electrochemical device is reduced. it can.

  In addition to the compound represented by the general formula (1), a copolymerizable carboxylic acid group-containing monomer can be used for the acrylate polymer. Specific examples include acrylic acid and methacrylic acid. Monobasic acid-containing monomers; dibasic acid-containing monomers such as maleic acid, fumaric acid, and itaconic acid. Among these, a dibasic acid-containing monomer is preferable, and itaconic acid is particularly preferable in terms of enhancing the binding property with the current collector and improving the electrode strength. These monobasic acid-containing monomers and dibasic acid-containing monomers can be used alone or in combination of two or more. The amount of the carboxylic acid group-containing monomer in the copolymerization is usually 0.1 to 50 parts by weight, preferably 0.5 to 20 parts per 100 parts by weight of the compound represented by the general formula (1). Part by weight, more preferably in the range of 1 to 10 parts by weight. When the amount of the carboxylic acid group-containing monomer is within this range, the binding property with the current collector is excellent, and the strength of the obtained electrode is improved.

  In addition to the compound represented by the general formula (1), a copolymerizable nitrile group-containing monomer can be used for the acrylate polymer. Specific examples of the nitrile group-containing monomer include acrylonitrile, methacrylonitrile, and the like. Among them, acrylonitrile is preferable in that the binding strength with the current collector is increased and the electrode strength can be improved. The amount of acrylonitrile is usually 0.1 to 40 parts by weight, preferably 0.5 to 30 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the compound represented by the general formula (1). Range. When the amount of acrylonitrile is within this range, the binding property with the current collector is excellent, and the strength of the resulting electrode is improved.

  The shape of the binder A is not particularly limited, but it has good binding properties with the current collector, and can suppress deterioration of the capacity of the prepared electrode and deterioration due to repeated charge and discharge, so that it is particulate. It is preferable that Examples of the particulate binder include those in which binder particles such as latex are dispersed in water, and powders obtained by drying such a dispersion.

  The glass transition temperature (Tg) of the binder A is preferably 50 ° C. or lower, more preferably −40 to 0 ° C. When the glass transition temperature (Tg) of the binder is within this range, it is excellent in binding property with a small amount of use, strong in electrode strength, rich in flexibility, and facilitates the electrode density by a pressing process at the time of electrode formation. Can be increased.

  The number average particle size of the binder A is not particularly limited, but is usually 0.0001 to 100 μm, preferably 0.001 to 10 μm, more preferably 0.01 to 1 μm. When the number average particle diameter of the binder A is within this range, an excellent binding force can be imparted to the electrode active material layer even with a small amount of use. Here, the number average particle diameter is a number average particle diameter calculated as an arithmetic average value obtained by measuring the diameter of 100 binder particles randomly selected in a transmission electron micrograph. The shape of the particles can be either spherical or irregular. These binders A can be used alone or in combination of two or more. The amount of the binder A in the electrode active material layer is usually 0.1 to 50 parts by weight, preferably 0.5 to 20 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the electrode active material. Part range. When the amount of the binder A in the electrode active material layer is within this range, sufficient adhesion between the obtained electrode active material layer and the current collector can be secured, the capacity of the electrochemical device is increased, and the internal resistance is decreased. can do.

  The electrode active material layer used in the present invention contains the electrode active material and the binder A as essential components, but may contain other components as necessary. Examples of other components include a conductive agent, a dispersant, and a surfactant.

(Conductive agent)
The conductive agent suitably used in the present invention is composed of an allotrope of particulate carbon that has conductivity and does not have pores that can form an electric double layer. Specifically, furnace black, acetylene black, and Examples thereof include conductive carbon black such as Ketjen Black (registered trademark of Akzo Nobel Chemicals Besloten Fennaut Shap). Among these, acetylene black and furnace black are preferable.

  The volume average particle diameter of the conductive agent suitably used in the present invention is preferably smaller than the volume average particle diameter of the electrode active material, and the range thereof is usually 0.001 to 10 μm, preferably 0.05 to 5 μm, more preferably. Is 0.01-1 μm. When the volume average particle diameter of the conductive material is within this range, high conductivity can be obtained with a smaller amount of use. These conductive materials can be used alone or in combination of two or more. The amount of the conductive material in the electrode active material layer is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 15 parts by weight, and particularly preferably 1 to 10 parts by weight with respect to 100 parts by weight of the electrode active material. Range. When the amount of the conductive material is within this range, the capacity of the battery using the obtained electrode can be increased and the internal resistance can be decreased.

(Surfactant)
The surfactant disperses the electrode active material, the binder A, and the conductive agent added as necessary, and reduces the surface tension of the slurry-like electrode composition described later, thereby improving the coating property. Let
Specific examples of the surfactant include anionic surfactants such as alkyl sulfate ester salts, alkylbenzene sulfonates, fatty acid salts, and naphthalenesulfonic acid formalin condensates, polyoxyethylene alkyl ethers, glycerin fatty acid esters, and the like. Nonionic surfactants, cationic surfactants such as alkylamine salts and quaternary ammonium salts, amphoteric surfactants such as alkylamine oxides and alkylbetaines, anionic surfactants and nonionic surfactants Surfactants are preferred, and anionic surfactants are particularly preferred from the viewpoint of excellent durability of the electrochemical element.

  When using a surfactant, the blending amount is in the range of 0.5 to 20 parts by weight, preferably 1.0 to 10 parts by weight, and 2.0 to 5 parts per 100 parts by weight of the electrode active material. Part by weight is particularly preferred. When the compounding amount of the surfactant is within this range, the durability of the electrochemical element is excellent.

(Dispersant)
Specific examples of the dispersant include cellulose derivatives such as carboxymethyl cellulose; poly (meth) acrylates such as sodium poly (meth) acrylate; polyvinyl alcohol, modified polyvinyl alcohol, polyethylene oxide; polyvinylpyrrolidone, polycarboxylic acid, oxidation Examples include starch, phosphate starch, casein, various modified starches, chitin, and chitosan derivatives. Among these, cellulose derivatives are particularly preferable.

  The cellulose derivative is a compound obtained by etherifying or esterifying at least a part of the hydroxyl group of cellulose, and is preferably water-soluble. Cellulose derivatives usually do not have a glass transition point. Specific examples include carboxymethyl cellulose, carboxymethyl ethyl cellulose, methyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose. Moreover, these ammonium salt and alkali metal salt are mentioned. Among these, a salt of carboxymethyl cellulose is preferable, and an ammonium salt of carboxymethyl cellulose is particularly preferable. The degree of etherification of the cellulose derivative is preferably 0.5 to 2, more preferably 0.5 to 1.5. Here, the degree of etherification is a value representing how many hydroxyl groups contained per 3 glucose units of cellulose are etherified on average. When the degree of etherification is within this range, the stability of the slurry containing the electrode composition is high, and solid matter sedimentation and aggregation are unlikely to occur. Furthermore, the coating property and fluidity | liquidity of a coating material improve by using a cellulose derivative.

The density of the electrode active material layer used in the present invention is not particularly limited, but is usually 0.30 to 10 g / cm ³ , preferably 0.35 to 5.0 g / cm ³ , and more preferably 0.40 to ³ . 0 g / cm ³ . The thickness of the electrode active material layer is not particularly limited, but is usually 5 to 1000 μm, preferably 20 to 500 μm, more preferably 30 to 300 μm.

(Conductive adhesive layer)
The conductive adhesive layer used for the electrode active material sheet with a support of the present invention contains a binder B and conductive particles.

(Binder B)
As the binder B used in the conductive adhesive layer, those exemplified as the binder A used in the electrode active material layer can be used. Specifically, it is a dispersion type binder having a property of being dispersed in a solvent. Examples of the dispersion-type binder include polymer compounds such as fluorine-based polymers, diene-based polymers, acrylate-based polymers, polyimides, polyamides, polyurethane-based polymers, and fluorine-based polymers, diene-based polymers, or acrylates. Polymers are preferable, and diene polymers or acrylate polymers are more preferable in that the withstand voltage can be increased and the energy density of the electrochemical device can be increased.

  In the present invention, the content of the binder B in the conductive adhesive layer is preferably 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight, particularly 100 parts by weight of the conductive particles. Preferably it is 2-10 weight part.

(Conductive particles)
The conductive particles used in the present invention are not particularly limited as long as they are conductive particles, but carbon particles are preferable. A carbon particle is a particle | grains which consist only of carbon or substantially only carbon. Specific examples of carbon particles include graphite having high conductivity due to the presence of delocalized π electrons (specifically, natural graphite, artificial graphite, etc.); Carbon black (specifically, acetylene black, ketjen black, other furnace blacks, channel blacks, thermal lamp blacks, etc.) which is a spherical aggregate having a structure; carbon fibers, carbon whiskers and the like. Among these, graphite or carbon black is particularly preferable in that the carbon particles of the conductive adhesive layer can be filled at a high density, the electron transfer resistance can be reduced, and the internal resistance of the electrochemical element can be reduced.

  As the carbon particles, those mentioned above may be used alone, but it is particularly preferable to use two types in combination. Specific combinations include graphite and carbon black, graphite and carbon fiber, graphite and carbon whisker, carbon black and carbon fiber, carbon black and carbon whisker, graphite and carbon black, graphite and carbon fiber, and carbon black. A combination of graphite and carbon fiber is preferable, and a combination of graphite and carbon black and graphite and carbon fiber is particularly preferable. When carbon particles are used in the above combination, the carbon particles of the conductive adhesive layer are filled with high density, so that the electron transfer resistance is reduced and the internal resistance of the electrochemical device is reduced.

The electrical resistivity of the carbon particles is preferably 0.0001 to 1 Ω · cm, more preferably 0.0005 to 0.5 Ω · cm, and particularly preferably 0.001 to 0.1 Ω · cm. When the electrical resistivity of the carbon particles is within this range, the electron transfer resistance of the conductive adhesive layer can be reduced and the internal resistance can be reduced. Here, the electrical resistivity is measured by using a powder resistance measurement system (MCP-PD51 type; manufactured by Dia Instruments Co., Ltd.) while measuring the resistance value while applying pressure to the carbon particles, and the resistance value converged with respect to the pressure. The electrical resistivity ρ (Ω · cm) = R × (S / d) is calculated from R (Ω), the area S (cm ² ) and the thickness d (cm) of the compressed carbon particle layer.

  The volume average particle diameter of the carbon particles is preferably 0.01 to 20 μm, more preferably 0.05 to 15 μm, and particularly preferably 0.1 to 10 μm. When the volume average particle diameter of the carbon particles is within this range, the carbon particles of the conductive adhesive layer are filled with high density, so that the electron transfer resistance is reduced and the internal resistance of the electrochemical device is reduced. Here, the volume average particle diameter is a volume average particle diameter calculated by measuring with a laser diffraction particle size distribution analyzer (SALD-3100; manufactured by Shimadzu Corporation).

  In the present invention, the volume average particle size distribution of the carbon particles suitably used for the conductive adhesive layer is preferably multimodal. Here, multimodal is a state in which a plurality of peaks appear when the existence frequency of particles having the particle size is plotted against the particle size. The volume average particle size distribution of the carbon particles is preferably bimodal having two peaks. Specifically, the carbon particles (a) having a volume average particle diameter of 0.01 μm or more and less than 1 μm, preferably 0.1 μm or more and 0.5 μm or less, and a volume average particle diameter of 1 μm or more and 10 μm or less, Preferably, it contains carbon particles (b) having a size of 1 μm or more and 5 μm or less. When the volume average particle size distribution of the carbon particles is bimodal, the carbon particles of the conductive adhesive layer are filled with high density, so that the electron transfer resistance is reduced and the internal resistance is reduced. Here, the volume average particle size distribution is a volume average particle size distribution calculated by measuring with a laser diffraction particle size distribution analyzer (SALD-3100; manufactured by Shimadzu Corporation).

  The weight ratio of the two types of carbon particles (a) and carbon particles (b) suitably used in the present invention is 0.05 to 1 in the ratio (a) / (b), and is 0.1 to 0.00. 8 is preferable, and 0.2 to 0.5 is particularly preferable. When the weight ratio of the two types of carbon particles is within this range, the carbon particles of the conductive adhesive layer are filled with high density, so that the electron transfer resistance is reduced and the internal resistance of the electrochemical device is reduced.

  In addition to the conductive particles and the binder B, the conductive adhesive layer may contain a dispersant for uniformly dispersing them. As the dispersant, the dispersant exemplified in the electrode active material layer can be used. Among them, cellulose derivatives are preferable, carboxymethyl cellulose salts are more preferable, and ammonium salts and sodium salts of carboxymethyl cellulose are particularly preferable.

  The amount of these dispersants can be used within a range that does not impair the effects of the present invention, and is not particularly limited, but is preferably 0.1 to 15 parts by weight with respect to 100 parts by weight of the conductive particles, More preferably, it is 0.5-10 weight part, Most preferably, it is the range of 0.8-5 weight part.

  The thickness of the conductive adhesive layer is usually 0.01 to 20 μm, preferably 0.1 to 10 μm, and particularly preferably 1 to 5 μm. When the thickness of the conductive adhesive layer is within the above range, good adhesiveness can be obtained and the electron transfer resistance can be reduced.

<Method for Producing Electrode Active Material Sheet with Support>
The method for producing an electrode active material sheet with a support of the present invention comprises a step of forming an electrode active material layer containing an electrode active material and a binder A on the surface of the support, and an electrode active material layer. And a step of forming a conductive adhesive layer containing the binder B and conductive particles.

(Method for forming electrode active material layer)
In the method for producing an electrode active material sheet with a support of the present invention, first, an electrode active material layer containing an electrode active material and a binder A is formed on the support surface.
As a method for forming the electrode active material layer, (1) an electrode composition obtained by kneading the binder A, the electrode active material and other components is formed into a sheet, and the obtained sheet-like electrode composition is supported. A method of laminating on a body, (2) a method of preparing a slurry-like electrode composition comprising a binder A, an electrode active material and other components, applying this on a support, and drying; 3) A method in which a composite particle comprising a binder A, an electrode active material and other components is prepared, and this is formed into a sheet on the surface of the support, and roll-pressed as necessary can be mentioned. Especially, the method of said (2) is preferable at the point which can form an electrode active material layer uniformly on the support body surface.

The slurry-like electrode composition used when the electrode active material layer is formed by the method (2) is a material constituting the electrode active material layer, specifically, the electrode active material, the binder A, and other necessary And an additive that is added according to the above and a dispersion medium.
As the electrode active material and the binder A, those exemplified in the electrode active material layer are used.
Other additives that may be added as necessary include conductive agents, dispersants, surfactants, and organic solvents other than the dispersion medium. As the conductive agent, dispersant, and surfactant, those exemplified for the electrode active material layer are used.

  Examples of the dispersion medium include water, N-methyl-2-pyrrolidone, tetrahydrofuran, toluene, and the like, and water is preferable from the viewpoint of easy drying of the slurry-like electrode forming material and excellent environmental load.

  In the method for producing an electrode active material sheet with a support of the present invention, the coating property of the slurry is improved by using an organic solvent other than the dispersion medium. In particular, when an organic solvent having a boiling point (normal pressure) of 50 to 150 ° C. is used, the organic solvent volatilizes simultaneously with volatilization of water when the electrode active material layer formed by applying the aqueous slurry is dried. The drying process can be simplified. Further, the organic solvent does not remain in the dried electrode active material layer, and the durability of the electrode is improved. Specific examples of the organic solvent include alcohols such as methanol, ethanol and isopropanol, alkyl esters such as methyl acetate and ethyl acetate, and ketones such as acetone and methyl ethyl ketone, preferably alcohols and alkyl esters. Alcohols are particularly preferable in view of excellent durability of the electrochemical element.

  When using an organic solvent, the compounding quantity is the range of 0.5-20 weight part with respect to 100 weight part of electrode active materials, 1.0-10 weight part is preferable, 2.0-5 weight Part is particularly preferred. When the blending amount of the organic solvent is within this range, the resulting electrochemical element is excellent in durability.

  Further, it is particularly preferable to use the above surfactant and an organic solvent in combination. By using the surfactant and the organic solvent in combination, the surface tension of the slurry-like electrode composition is further reduced, and the productivity is improved. In this case, the total amount of the surfactant and the organic solvent is in the range of 0.5 to 20 parts by weight, preferably 1.0 to 10 parts by weight, with respect to 100 parts by weight of the electrode active material. ˜5 parts by weight is particularly preferred.

  The slurry-like electrode composition is prepared by kneading an electrode active material, a binder A, and a conductive agent, a dispersant, a surfactant, and an organic solvent other than the dispersion medium, if necessary, in the dispersion medium. Can be manufactured.

  As a manufacturing method of a slurry-like electrode composition, it can manufacture by mixing a dispersion medium and each said component using a mixer. As the mixer, a ball mill, a sand mill, a pigment disperser, a pulverizer, an ultrasonic disperser, a homogenizer, a planetary mixer, a Hobart mixer, and the like can be used. Also, the electrode active material and the conductive agent added as necessary are first mixed using a mixer such as a crusher, a planetary mixer, a Henschel mixer, and an omni mixer, and then a binder is added and mixed uniformly. The method of doing is also preferable. By adopting this method, a uniform slurry can be easily obtained.

  The viscosity of the slurry used in the present invention varies depending on the type of coating machine and the shape of the coating line, but is usually 100 to 100,000 mPa · s, preferably 1,000 to 50,000 mPa · s. Preferably, it is 5,000 to 20,000 mPa · s.

  The method for applying the slurry-like electrode composition onto the support surface is not particularly limited. Examples thereof include a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, and a brush coating method. The coating thickness of the slurry is appropriately set according to the thickness of the target electrode active material layer.

  As a method for forming the electrode active material layer, a specific example in the case of adopting the method of (2), that is, a method of applying a slurry-like electrode composition on the surface of a support and drying it is shown in FIG. Show. In FIG. 1, the winding body of the support body 1 is attached to the unwinder 10, the support body 1 is sent out from the unwinder 10, and the slurry-like electrode composition is applied from the coating machine 3 to the roughened surface of the support body 1. And a coating layer is formed on the roughened surface of the support 1. In the figure, the formed electrode active material layer is not shown. Next, the support having the coating layer formed on the surface is introduced into the dryer 4, and the coating layer is dried to form an electrode active material layer. Thereafter, the support (electrode active material sheet with support) on which the electrode active material layer is formed is wound up by the winder 11 to obtain a wound body of the electrode active material sheet with support.

The drying temperature and drying time of the slurry-like electrode composition coated on the surface of the support are sufficient to dry the slurry-like electrode composition coated on the support, and the materials used are dried without being oxidized or dissolved. If it can do, it will not be specifically limited.
A drying temperature is 50-200 degreeC normally, Preferably it is 80-150 degreeC, More preferably, it is 100-130 degreeC. By setting the drying temperature within this range, the material used can be dried without being oxidized or dissolved.
The drying time is appropriately set according to the type of the support or the slurry-like electrode composition, the coating speed, and the length of the drying furnace.

(Method for forming conductive adhesive layer)
In the method for producing an electrode active material sheet with a support of the present invention, a conductive adhesive layer containing a binder B and conductive particles is formed on the electrode active material layer formed on the support surface. To do.
As a method for forming the conductive adhesive layer, (i) a conductive adhesive composition obtained by kneading the binder B, conductive particles and other components is formed into a sheet, and the resulting sheet-like electrode composition is obtained. And (ii) preparing a slurry-like conductive adhesive composition comprising binder B, conductive particles and other components, and forming the electrode active material layer on the electrode active material layer. (Iii) A composite particle comprising binder B, conductive particles and other components is prepared, and this is formed into a sheet on the electrode active material layer, and optionally rolled. (Iv) A conductive adhesive layer is formed by applying and drying a slurry-like conductive adhesive composition containing binder B, conductive particles and other components on a release film. And (v) a binder B, conductive particles, and a method of transferring this onto the electrode active material layer; A composite particle comprising the above components is prepared, formed into a sheet on a release film, and roll-pressed as necessary to form a conductive adhesive layer, which is then transferred onto the electrode active material layer, etc. Is mentioned. Among these, the method (ii) is preferable in that the conductive adhesive layer can be uniformly formed on the surface of the electrode active material layer.

The slurry-like conductive adhesive composition used in the case of forming the conductive adhesive layer by the method (ii) is a material constituting the conductive adhesive layer, specifically, binder B, conductive Particles, other additives that are added as necessary, and a dispersion medium.
As the binder B and the conductive particles, those exemplified for the conductive adhesive layer are used.
Other additives that may be added as necessary include dispersants, surfactants, and organic solvents other than the dispersion medium. As the dispersant and the surfactant, those exemplified in the electrode active material layer are used.

  Examples of the dispersion medium include water, N-methyl-2-pyrrolidone, tetrahydrofuran, toluene, and the like, and water is preferable from the viewpoint of easy drying of the slurry-like electrode forming material and excellent environmental load.

  In the method for producing an electrode active material sheet with a support of the present invention, the coating property of the slurry is improved by using an organic solvent other than the dispersion medium. In particular, when an organic solvent having a boiling point (normal pressure) of 50 to 150 ° C. is used, the organic solvent volatilizes simultaneously with the volatilization of water when the conductive adhesive layer formed by applying the aqueous slurry is dried. The drying process can be simplified. In addition, the organic solvent does not remain in the conductive adhesive layer after drying, and the durability of the electrode is improved. Specific examples of the organic solvent include alcohols such as methanol, ethanol and isopropanol, alkyl esters such as methyl acetate and ethyl acetate, and ketones such as acetone and methyl ethyl ketone, preferably alcohols and alkyl esters. Alcohols are particularly preferable in view of excellent durability of the electrochemical element.

  When using an organic solvent, the compounding quantity is 0.5-20 weight part with respect to 100 weight part of electroconductive particles, 1.0-10 weight part is preferable, 2.0-5 weight Part is particularly preferred. When the blending amount of the organic solvent is within this range, the resulting electrochemical element is excellent in durability.

  Further, it is particularly preferable to use the above surfactant and an organic solvent in combination. By using the surfactant and the organic solvent in combination, the surface tension of the slurry-like conductive adhesive composition is further reduced, and the productivity is improved. In this case, the total amount of the surfactant and the organic solvent is in the range of 0.5 to 20 parts by weight, preferably 1.0 to 10 parts by weight, with respect to 100 parts by weight of the conductive particles. ˜5 parts by weight is particularly preferred.

  The slurry-like conductive adhesive composition is prepared by kneading binder B and conductive particles, and an organic solvent other than a dispersant, a surfactant, and a dispersion medium added as necessary in the dispersion medium. Can be manufactured.

  As a manufacturing method of a slurry-like electroconductive adhesive composition, a dispersion medium and each said component can be mixed and manufactured using a mixer. As the mixer, a ball mill, a sand mill, a pigment disperser, a pulverizer, an ultrasonic disperser, a homogenizer, a planetary mixer, a Hobart mixer, and the like can be used. Also, the electrode active material and the conductive agent added as necessary are first mixed using a mixer such as a crusher, a planetary mixer, a Henschel mixer, and an omni mixer, and then a binder is added and mixed uniformly. The method of doing is also preferable. By adopting this method, a uniform slurry can be easily obtained.

  The viscosity of the slurry-like conductive adhesive composition used in the present invention varies depending on the type of coating machine and the shape of the coating line, but is usually 100 to 100,000 mPa · s, preferably 1,000. 50,000 mPa · s, more preferably 5,000 to 20,000 mPa · s.

  The method for applying the slurry-like conductive adhesive composition onto the electrode active material layer is not particularly limited. Examples thereof include a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, and a brush coating method. The application thickness of the slurry is appropriately set according to the thickness of the target conductive adhesive layer.

<Method for producing electrode for electrochemical device>
The method for producing an electrode for an electrochemical device of the present invention includes a step of bonding an electrode active material sheet with a support to a current collector, and separating the support from the electrode active material sheet with a support bonded to the current collector The process of carrying out.

(Process of bonding the electrode active material sheet with support to the current collector)
In the method for producing an electrode for an electrochemical element of the present invention, an electrode active material sheet with a support is bonded to a current collector.

(Current collector)
The current collector is used for taking out an electric current from the electrode active material layer, and the type of material constituting the current collector can be, for example, metal, carbon, conductive polymer, etc. For this, metal is used. For example, various materials proposed for applications such as batteries and capacitors can be used. The positive electrode current collector is preferably aluminum, stainless steel, and the negative electrode current collector is preferably stainless steel, copper, nickel, etc. Can be used. The current collector may have a structure having no through-hole, but the method of the present invention particularly has a current collector having a through-hole (hereinafter, sometimes referred to as “perforated current collector”). Suitable for forming an electrode active material layer on top. Therefore, the current collector is, for example, an expanded metal, a punching metal, a metal net, a foam, an etching foil provided with through holes by etching, or a current collector with protrusions provided with protrusions and through holes using an embossing roll. Etc. are preferably used.

  In the method for producing an electrode for an electrochemical device of the present invention, the shape of the aperture portion of the apertured current collector when the apertured current collector is used as the current collector is not particularly limited, and the aperture ratio is preferably It is 10% to 90%, more preferably 20% to 60%, and particularly preferably 40% to 60%. The aperture ratio is determined by planar observation of the perforated current collector. Specifically, the aperture ratio is determined by observing the perforated current collector in a plane and calculating the area of the through holes per unit area.

  By setting the aperture ratio of the perforated current collector within the above range, it is possible to suppress the capacity variation between lots when the electrochemical device is manufactured. In an electrochemical element using a current collector that does not have a normal aperture, if a non-facing surface is formed where the electrodes do not face each other when a stacked electrochemical element is produced, the non-facing surface is static. The electric capacity cannot be taken out. Furthermore, if the amount of active material per unit area of the electrode varies, the actual capacitance that can be taken out may be smaller than the capacitance calculated from the weight of the active material. It also leads to deterioration factors. For this reason, capacity variation occurs between lots of electrochemical elements, and the lifetime of the electrochemical elements may be further shortened. This is because the diffusion of electrolyte ions occurs only on the opposing surface of the positive and negative electrodes. However, by using a perforated current collector, electrolyte ions pass through the current collector and diffuse, so that the capacitance can be taken out from the non-facing surface where the electrodes do not face each other. Furthermore, even when using electrodes with different amounts of active material per unit area of the electrode, as long as the total weight of the electrode active material is matched, capacity balance can be easily achieved in the capacitor cell. Capacity variation between lots can be suppressed. In addition, since there is no charge bias in the cell, the lifetime of the electrochemical element can be extended.

  In addition, when the aperture ratio of the current collector is too high to support lithium on the negative electrode active material, the time required to support it is short, and unevenness of lithium support is unlikely to occur, but the strength of the current collector is It tends to drop and become wrinkled and cut. In addition, it becomes difficult to hold the active material or the like in the through-hole, and problems such as a decrease in yield during electrode manufacturing occur due to falling off of the active material or the like, or breakage of the electrode.

  On the other hand, when the aperture ratio is too low, the time required to support lithium on the negative electrode active material becomes long and problems such as a decrease in production efficiency and an increase in variation in cell characteristics occur, but the strength of the current collector is The electrode yield is increased because the active material is less likely to fall off. The aperture ratio and the hole diameter of the current collector are desirably selected as appropriate within the above-mentioned ranges in consideration of the battery structure (stacked type, wound type, etc.) and productivity.

  The current collector is strip-shaped, and the thickness is not particularly limited, but is preferably 5 to 50 μm, and more preferably 10 to 40 μm. The width is not particularly limited, but is preferably about 100 to 1000 mm, more preferably about 200 to 500 mm.

In the manufacturing method of the electrode for electrochemical elements of this invention, it bonds together by crimping | bonding the electroconductive adhesive layer of the electrode active material sheet with a support body to a collector.
The linear pressure when the electrode active material sheet with support is pressure-bonded to the current collector is not particularly limited as long as the shape of the surface of the support is not impaired, but is usually 50 to 2,000 kN / m, preferably 100 to 1,000 kN / m, particularly preferably 200 to 500 kN / m. When the linear pressure during crimping is within this range, the electrode active material layer and the conductive adhesive layer can be uniformly bonded to the current collector, and the electrode strength is excellent.

  In the method for producing an electrode for an electrochemical element of the present invention, heat may be applied simultaneously with pressure bonding (hot pressing). Specific examples of the hot press method include a batch hot press and a continuous hot roll press, and a continuous hot roll press capable of improving productivity is preferable. The temperature of the hot press is not particularly limited, but is usually 50 to 200 ° C, preferably 70 to 150 ° C. When the temperature of the hot press is within this range, the electrode active material layer and the conductive adhesive layer can be uniformly bonded to the current collector, and the electrode strength is excellent.

  In the method for producing an electrode for an electrochemical element of the present invention, the electrode active material sheet with a support may be pressure-bonded to the current collector immediately after the application of the slurry-like conductive adhesive composition. It is particularly preferred that the processed conductive adhesive composition is dried and then pressure-bonded to the current collector. By drying the coated conductive adhesive composition, the layer thickness of the conductive adhesive layer becomes constant and the strength is improved, so that the pressure bonding to the current collector is facilitated. Moreover, since it crimps | bonds to a collector after drying, an electrode active material layer and a conductive adhesive layer can be formed only in the required location on a collector. Further, when the support is separated after being crimped to the current collector, part of the electrode active material layer can be prevented from remaining on the support.

  Examples of the drying method include drying by warm air, hot air, low-humidity air, vacuum drying, and drying by irradiation with (far) infrared rays or electron beams. Among these, a drying method by irradiation with far infrared rays is preferable. The drying temperature and drying time in the present invention are preferably a temperature and a time at which the solvent in the slurry applied to the current collector can be completely removed, and the drying temperature is 100 to 300 ° C, preferably 120 to 250 ° C. The drying time is usually 1 minute to 60 minutes, preferably 5 minutes to 30 minutes.

In the method for producing an electrode for an electrochemical element of the present invention, the support is separated from the electrode active material sheet with the support bonded to the current collector.
The method for separating the support from the electrode active material sheet with the support pressure-bonded to the current collector is not particularly limited. For example, the current collector with the electrode active material layer and the conductive adhesive layer, and the support are combined. It can be easily separated by winding on separate rolls.

  A specific embodiment of the method for producing an electrode for an electrochemical element of the present invention is shown in FIG. In the figure, the electrode active material layer and the conductive adhesive layer are not shown. In FIG. 2, the wound body of the electrode active material sheet with a support is attached to the unwinder 12, and the electrode active material sheet with a support is sent out. Separately, the current collector 2 is attached to the unwinder 14 and the current collector is sent out. Next, the electrode active material sheet with support and the current collector 2 are introduced into a laminator 16 equipped with a heating mechanism, and hot pressing is performed, and the electrode active material sheet with support is pressure bonded to the current collector 2. Next, the support was separated from the electrode active material sheet with support pressed onto the current collector, the separated support was wound up by the winder 13, and the electrode active material layer and the conductive adhesive layer were transferred. The current collector 2 is wound up by a winder 15 to obtain a current collector with an electrode active material layer and a conductive adhesive layer.

  Similarly, the electrode active material layer and the conductive adhesive layer are transferred to the other surface of the current collector on which the electrode active material layer and the conductive adhesive layer are formed using the electrode active material sheet with a support. Thus, an electrode for an electrochemical device in which an electrode active material layer and a conductive adhesive layer are formed on both surfaces of the current collector can also be produced. Furthermore, as shown in FIG. 2, an electrode active material layer and a conductive adhesive layer may be simultaneously formed on both sides of the current collector by the above method.

<Electrochemical element>
The electrochemical device of the present invention includes an electrode for an electrochemical device obtained by the production method of the present invention. Examples of the electrochemical element include a lithium ion secondary battery, an electric double layer capacitor, and a hybrid capacitor. An electric double layer capacitor and a hybrid capacitor are preferable, and a hybrid capacitor is more preferable. Hereinafter, the case where the electrode for electrochemical elements obtained by the manufacturing method of the present invention is used for an electrode for an electric double layer capacitor or an electrode for a hybrid capacitor will be described.

The electric double layer capacitor is composed of an electrode, a separator and an electrolytic solution, and the electrode for an electrochemical element of the present invention is used as the electrode.
The hybrid capacitor is composed of a positive electrode, a negative electrode, a separator, and an electrolytic solution, and an electrode for an electrochemical element obtained by the production method of the present invention is used as the positive electrode or the negative electrode. In the lithium ion capacitor, the positive electrode and the negative electrode are preferably electrodes for electrochemical devices obtained by the production method of the present invention.

  The separator is not particularly limited as long as it can insulate between the electrodes and allow a cation and an anion to pass therethrough. Specifically, polyolefins such as polyethylene and polypropylene, microporous membranes or non-woven fabrics made of rayon, aramid or glass fiber, and porous membranes mainly made of pulp called electrolytic capacitor paper can be used. The separator is disposed between the electrodes so that the pair of electrode active material layers face each other, and an element is obtained. Although the thickness of a separator is suitably selected according to a use purpose, it is 1-100 micrometers normally, Preferably it is 10-80 micrometers, More preferably, it is 20-60 micrometers.

  The electrolytic solution is usually composed of an electrolyte and a solvent. The electrolyte may be cationic or anionic. As the cationic electrolyte, (1) imidazolium, (2) quaternary ammonium, (3) quaternary phosphonium, (4) lithium and the like as shown below can be used.

(1) Imidazolium 1,3-Dimethylimidazolium, 1-ethyl-3-methylimidazolium, 1,3-diethylimidazolium, 1,2,3-trimethylimidazolium, 1,2,3,4-tetra Methylimidazolium, 1,3,4-trimethyl-ethylimidazolium, 1,3-dimethyl-2,4-diethylimidazolium, 1,2-dimethyl-3,4-diethylimidazolium, 1-methyl-2, 3,4-triethylmethylimidazolium, 1,2,3,4-tetraethylimidazolium, 1,3-dimethyl-2-ethylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1,2,3 -Triethylimidazolium, etc. (2) Quaternary ammonium tetramethylammonium, ethyltrimethylammonium, diethyl Tetraalkylammonium such as methylammonium, triethylmethylammonium, tetraethylammonium, trimethylpropylammonium, etc. (3) Quaternary phosphonium Tetramethylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, methyltriethylphosphonium, methyltributylphosphonium, dimethyldiethylphosphonium 4) Lithium

In addition, examples of the anionic electrolyte include PF ₆ ⁻ , BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , N (RfSO ₃ ) ²⁻ , C (RfSO ₃ ) ³⁻ , RfSO ₃ ⁻ (Rf is 1 carbon number, respectively). ˜12 fluoroalkyl groups), F ⁻ , ClO ₄ ⁻ , AlCl ₄ ⁻ , AlF ₄ ^{− and the} like. These electrolytes can be used alone or in combination of two or more.

  The solvent of the electrolytic solution is not particularly limited as long as it is generally used as a solvent for the electrolytic solution. Specifically, carbonates such as propylene car boat, ethylene carbonate and butylene carbonate; lactones such as γ-butyrolactone; sulfolanes; nitriles such as acetonitrile; These can be used alone or as a mixed solvent of two or more. Of these, carbonates are preferred.

  An electric double layer capacitor or a hybrid capacitor can be obtained by impregnating the above element with an electrolytic solution. Specifically, the capacitor element can be manufactured by winding, stacking, or folding into a container as necessary, and pouring the electrolyte into the container and sealing it. Further, a device in which an element is previously impregnated with an electrolytic solution may be stored in a container. Any known container such as a coin shape, a cylindrical shape, or a square shape can be used as the container.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to these Examples. In the examples and comparative examples, “part” and “%” are based on weight unless otherwise specified. Each characteristic in an Example and a comparative example is measured in accordance with the following method.

(Measurement of arithmetic average roughness (Ra) of the roughened surface of the support)
Measured based on JIS B 0601-2001. The arithmetic average roughness (Ra) of the support surface is obtained by drawing a roughness curve using a nano-scale hybrid microscope (VN-8010) manufactured by Keyence Corporation, and calculating by the following formula. L is the measurement length, and x is the deviation from the average line to the measurement curve.

(Contact angle of the release surface of the support with water)
2 μL of pure water is dropped on the release treatment surface of the support, the static contact angle is measured, and the contact angle with water on the support surface is calculated by the θ / 2 method.

(Transfer rate of electrode active material layer)
The weight of the electrode active material layer before transfer is calculated from the weight of the support and the weight of the electrode active material sheet with the support. Next, the support-attached electrode active material sheet is hot pressed onto the current collector, and then the support is peeled off, and the electrode active material layer is transferred to the current collector. Then, the weight of the electrode active material layer remaining on the support after the transfer is measured, and the transfer rate is calculated from the following equation.
Transfer rate (%) = (weight of electrode active material layer on support before transfer−weight of electrode active material layer remaining on support after transfer) / (weight of electrode active material layer before transfer) × 100
In the above equation, the weight of the electrode active material layer on the support before transfer and the weight of the electrode active material layer remaining on the support after transfer are obtained by the following equations.
Weight of electrode active material layer on support before transfer = weight of support after formation of electrode active material layer−weight of support before formation of electrode active material layer Weight of electrode active material layer remaining on support after transfer = Support weight after transfer-Support weight before electrode active material layer formation

(Thickness accuracy of electrode active material layer)
The thickness accuracy of the electrode active material layer is determined by using an eddy current displacement sensor (sensor head part EX-110V, amplifier unit part EX-V02: manufactured by Keyence Corporation) after forming the electrode active material layer on both sides of the current collector. To measure. The thickness of each electrode active material layer is measured at intervals of 2 cm in the longitudinal direction and at an interval of 5 cm in the width direction, and the average value thereof is taken as the thickness of the electrode active material layer, and thickness accuracy (thickness variation coefficient) is calculated.

(Electrical characteristics of electric double layer capacitor)
The electrical characteristics of the electric double layer capacitor are determined by a charge / discharge test of the electric double layer capacitor. Charging current is performed using a current value at which the current value per unit area of the electrode is 3.3 mA / cm ^2, and when the voltage reaches 2.7 V, the voltage is maintained and constant voltage charging is performed. Charging is completed when the current value drops to 0.165 mA / cm ² . Then, immediately after the end of charging, constant current discharging is performed until the voltage reaches 0 V at a current value similar to that used during charging. The capacitance is calculated from the amount of electric power at the time of discharge using an energy conversion method.

Next, using this capacitance, charging is started at a constant current of 5 mA / F so that the charging / discharging speed of the electric double layer capacitor is constant, and the charging times of constant current charging and constant voltage charging are matched. When the charging is completed for 20 minutes, the charging is completed. Then, immediately after the charging is completed, constant current discharging is performed until the voltage reaches 0 V at a current value similar to that used for charging.
The internal resistance is a value obtained by dividing the amount of voltage drop at the start of discharge from the extrapolation of the approximate curve by the least square method of the voltage data from the start of discharge to the predetermined time divided by the discharge current value, and the resistivity per volume, that is, the volume Expressed as resistivity. However, the predetermined time is 10% of the total discharge time. It shows that it is excellent in power density, so that volume resistivity is small.
The capacitance is calculated from the amount of electric power during discharge using an energy conversion method, and is calculated as the capacitance per volume of the electrode active material layer used in the electric double layer capacitor, that is, the capacitance density. It shows that it is excellent in energy density, so that an electrostatic capacitance density is large.

(Electric characteristics of hybrid capacitor)
The electrical characteristics of the hybrid capacitor are determined by a charge / discharge test of the hybrid capacitor. The charging current is performed using a current value at which the current value per unit area of the electrode is 3.3 mA / cm ^2. When the voltage reaches 3.8 V, the voltage is maintained and constant voltage charging is performed. Charging is completed when the current value drops to 0.165 mA / cm ² . Next, immediately after the end of charging, constant current discharging is performed until the voltage reaches 2.1 V at a current value similar to that used during charging. The capacitance is calculated from the amount of electric power at the time of discharge using an energy conversion method.

Next, using this capacitance, charging is started at a constant current of 5 mA / F so that the charging / discharging speed of the hybrid capacitor is constant, and the charging time of constant current charging and constant voltage charging is combined for 20 minutes. The charging is completed when the charging is performed, and then constant current discharging is performed immediately after the charging is completed until the voltage reaches 2.1 V at a current value similar to that used during charging.
The internal resistance is a value obtained by dividing the amount of voltage drop at the start of discharge from the extrapolation of the approximate curve by the least square method of voltage data from the start of discharge to the predetermined time divided by the discharge current value, and the resistivity per volume, that is, the volume Expressed as resistivity. However, the predetermined time is 10% of the total discharge time. It shows that it is excellent in power density, so that volume resistivity is small.
The capacitance is calculated from the amount of electric power at the time of discharge using an energy conversion method, and is calculated as the capacitance per volume of the electrode active material layer used in the hybrid capacitor, that is, the capacitance density. It shows that it is excellent in energy density, so that an electrostatic capacitance density is large.

<Example 1>
(Production of slurry-like electrode composition)
Carboxymethylcellulose ammonium salt having a degree of etherification of 0.6 and a 1% aqueous solution having a viscosity of 30 mPa · s is dissolved in 213.2 parts of ion-exchanged water, and a volume average particle diameter of 0. 50 parts of 035 μm acetylene black (Denka black powder: manufactured by Denki Kagaku Kogyo Co., Ltd.) is added and mixed and dispersed using a planetary mixer to obtain a conductivity imparting agent dispersion having a solid content of 20%.

26 parts of the resulting conductivity imparting agent dispersion, 100 parts of activated carbon powder having an average particle size of 5 μm and a specific surface area of 2000 m ² / g as the electrode active material, and water having an acrylate polymer solid content concentration of 40% as the binder A An appropriate amount of water is added to 7.5 parts of the dispersion and 1 part of carboxymethyl cellulose ammonium salt having a degree of etherification of 0.6 and a 1% aqueous solution having a viscosity of 900 mPa · s, and mixed and dispersed using a planetary mixer. A slurry-like electrode composition having a viscosity of between 5,000 and 20,000 mPa · s is obtained. The acrylate polymer used as the binder A is obtained by emulsion polymerization of 76 parts of 2-ethylhexyl acrylate, 20 parts of acrylonitrile and 4 parts of itaconic acid, and has a number average particle size of 0.2 μm and a glass transition. A copolymer having a temperature (Tg) of −20 ° C. is used.

(Manufacture of conductive adhesive)
As conductive particles, 80 parts of graphite having a volume average particle diameter of 3.7 μm (KS-6: manufactured by Timcal) and 20 parts of carbon black having a volume average particle diameter of 0.4 μm (Super-P: manufactured by Timcar), as a dispersant. 4 parts of carboxymethylcellulose ammonium salt having a degree of etherification of 0.6 and a viscosity of 1% aqueous solution of 30 mPa · s, 261 parts of water in 8 parts of aqueous dispersion of 40% solid content of acrylate polymer as binder B In addition, it is mixed and dispersed using a planetary mixer to obtain a slurry-like conductive adhesive composition having a solid content concentration of 30%. The acrylate polymer used as the binder B is obtained by emulsion polymerization of 76 parts of 2-ethylhexyl acrylate, 20 parts of acrylonitrile and 4 parts of itaconic acid, and has a number average particle size of 0.2 μm and a glass transition. A copolymer having a temperature (Tg) of −20 ° C. is used.

(Manufacture of electrode active material sheet with support)
As a support, a PET film (thickness 75 μm, tensile strength 200 MPa) obtained by kneading a mat material so as to have a surface roughness Ra of 0.14 μm is used. The surface of the support having a surface roughness Ra of 0.14 μm was coated with the slurry-like electrode composition at a rate of 8 m / min using a die coater, then dried in a drying furnace and thickened on the support. An electrode active material layer having a thickness of 110 μm is formed. Further, the slurry-like conductive adhesive composition was applied onto the electrode active material layer at a speed of 15 m / min using a die coater, and then dried in a drying furnace to have a thickness of 4 μm on the electrode active material layer. The conductive adhesive layer is formed and wound up to obtain a roll-like electrode active material sheet with a support.

(Manufacture of electrodes for electrochemical devices)
The electrode active material sheet with a support obtained above is laminated on one side of a 30 μm thick aluminum punching metal (opening ratio: 50%, manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.) at a speed of 6 m / min (temperature: 100). Then, the support is peeled off, and a conductive adhesive layer and an electrode active material layer are formed on one surface of the current collector.
A support-attached electrode active material sheet is bonded to the other surface of the current collector in the same manner as described above to produce a double-sided electrode having a conductive adhesive layer and an electrode active material layer on both sides of the current collector.
The transfer rate of the electrode active material layer to the current collector is 98%. The thickness accuracy of the electrode active material layer of the obtained electrode is within 3%.

(Preparation of measurement cell)
In the electrode obtained above, the uncoated part where the conductive adhesive layer and the electrode active material layer are not formed is left 2 cm × 2 cm wide, and the electrode active material layer is 5 cm long × 5 cm wide. cut out. A tab material made of aluminum having a length of 7 cm, a width of 1 cm, and a thickness of 0.01 cm is ultrasonically welded to the uncoated portion. Two sets are prepared and dried at 200 ° C. for 20 hours. The two electrode active material layer surfaces are opposed to each other, and a separator made of a rayon-based porous film having a length of 6 cm × width of 6 cm and a thickness of 35 μm is sandwiched therebetween. This is housed in a laminate film, vacuum impregnated with an electrolyte so that no air remains, and then the laminate film is pressure-bonded with a laminator and sealed to produce an electric double layer capacitor. As the electrolytic solution, a solution obtained by dissolving tetraethylammonium borofluoride at a concentration of 1.0 mol / L in propylene carbonate is used. The storage of the electrode after heat treatment and the assembly of the capacitor are performed in a dry room having a dew point temperature of −60 ° C. The electric double layer capacitor obtained has a capacitance density of 14 F / cc and a volume resistivity of 470 Ω · cm. The results are shown in Table 1.

<Example 2>
The support was carried out in the same manner as in Example 1 except that a PET film (thickness 75 μm, tensile strength 200 MPa) that was roughened by sandblasting so that the surface roughness Ra was 0.4 μm was used as the support. A body-attached electrode active material sheet, an electrode, and an electric double layer capacitor are produced.
The transfer rate of the electrode active material layer to the current collector is 99%. The thickness accuracy of the electrode active material layer of the obtained electrode is within 3%. The obtained electric double layer capacitor had a capacitance density of 14 F / cc and a volume resistivity of 500 Ω · cm. The results are shown in Table 1.

<Example 3>
As a support, a PET film (thickness 75 μm, tensile strength 200 MPa, mold release treatment, which has been subjected to a surface roughening treatment by sandblasting so that the surface roughness Ra becomes 1.2 μm, and is subjected to a release treatment by applying and curing a silicone resin. A support-attached electrode active material sheet, an electrode, and an electric double layer capacitor are produced in the same manner as in Example 1 except that the contact angle with water on the treated surface is 100 °.
The transfer rate of the electrode active material layer to the current collector is 94%. The thickness accuracy of the electrode active material layer of the obtained electrode is within 4%. The obtained electric double layer capacitor has a capacitance density of 14 F / cc and a volume resistivity of 540 Ω · cm. The results are shown in Table 1.

<Example 4>
A support-supported electrode active material sheet, an electrode, and an electric double layer capacitor were prepared in the same manner as in Example 1 except that a PET film (thickness: 75 μm) having a surface roughness Ra of 0.04 μm was used as the support. To do.
The transfer rate of the electrode active material layer to the current collector is 94%. The thickness accuracy of the electrode active material layer of the obtained electrode is within 4%. The obtained electric double layer capacitor has a capacitance density of 14 F / cc and a volume resistivity of 530 Ω · cm. The results are shown in Table 1.

<Example 5>
Other than using a PET film with a surface roughness Ra of 0.04 μm (thickness 75 μm, contact angle with water on the release treatment surface: 97 °) that has been peeled off by applying and curing an alkyd resin as a support. In the same manner as in Example 1, an electrode active material sheet with a support, an electrode, and an electric double layer capacitor are produced.
The transfer rate of the electrode active material layer to the current collector is 97%. The thickness accuracy of the electrode active material layer of the obtained electrode is within 4%. The obtained electric double layer capacitor has a capacitance density of 14 F / cc and a volume resistivity of 510 Ω · cm. The results are shown in Table 1.

(Comparative Example 1)
The slurry-like conductive adhesive composition obtained in Example 1 was applied to both sides of an aluminum punching metal having a thickness of 30 μm at a speed of 2 m / min using a roll coater, and then dried in a drying furnace. Then, a conductive adhesive layer having a thickness of 4 μm is formed on both sides of the current collector.
Furthermore, on this conductive adhesive layer, the slurry-like electrode composition obtained in Example 1 was applied at a speed of 5 m / min using a die coater, and then dried in a drying furnace to obtain a conductive property. An electrode active material layer having a thickness of 110 μm is formed on the adhesive layer. This is also performed on the other conductive adhesive layer to obtain an electrode for an electrochemical element. The thickness accuracy of the electrode active material layer of the obtained electrode is within 5%.
An electric double layer capacitor is produced in the same manner as in Example 1 except that the electrode for electrochemical element is used as the electrode for electrochemical element.
The electric double layer capacitor obtained has a capacitance density of 14 F / cc and a volume resistivity of 520 Ω · cm. The results are shown in Table 1.

<Example 6>
(Manufacture of positive electrode for hybrid capacitor)
In the same manner as in Example 1, a double-sided electrode having a conductive adhesive layer and an electrode active material layer on both sides of an aluminum punching metal (opening ratio 50%, manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.) having a thickness of 30 μm is prepared. . This is used as the positive electrode of the hybrid capacitor electrode.

(Manufacture of negative electrode for hybrid capacitor)
100 parts of graphite (KS-4, manufactured by Timcal) having a volume average particle size of 2.7 μm, 2 parts of an aqueous dispersion of a diene polymer having a solid content concentration of 40%, and the degree of etherification is 0.6. A 1% aqueous solution having a viscosity of 900 mPa · s is added to 2 parts of carboxymethylcellulose ammonium salt corresponding to the solid content, and mixed and dispersed using a planetary mixer, and the viscosity is 5,000 to 20,000 mPas. A slurry-like electrode composition for negative electrode that falls between s is obtained. The diene polymer is obtained by emulsion polymerization of 46.5 parts of styrene, 50 parts of butadiene, 3 parts of methacrylic acid, and 0.5 part of acrylic acid, Tg is −20 ° C., and the number average particle diameter is 0. A 25 μm copolymer is used.

A PET film (thickness: 75 μm, tensile strength: 200 MPa) that has been roughened by sandblasting so that the surface roughness Ra is 0.4 μm is used as a support, and the slurry-like electrode composition for negative electrode is die coater. The electrode active material sheet with a support having an electrode active material layer having a thickness of 50 μm is prepared by winding at a rate of 12 m / min using a substrate and then dried in a drying furnace. A body-attached electrode active material sheet is obtained. A wound electrode active material sheet is wound on a laminator (temperature: 100 ° C., linear pressure) at a speed of 12 m / min on both sides of a 20 μm-thick copper punching metal (opening ratio: 50%, manufactured by Fukuda Metal Foil Co., Ltd.). 300 kN / m), and finally the support is peeled off to produce a double-sided electrode having an electrode active material layer with a single-sided thickness of 25 μm. This double-sided electrode is used as the negative electrode of the hybrid capacitor electrode.
The transfer rate of the electrode active material layer to the current collector is 97%. The thickness accuracy of the electrode active material layer of the obtained electrode is within 3%.

(Preparation of measurement cell)
Each of the positive electrode and the negative electrode obtained above is formed by leaving an uncoated part where the conductive adhesive layer and the electrode active material layer are not formed, and leaving an electrode active material layer of 2 cm in length and 2 cm in width. Cut out the part to be 5cm long x 5cm wide. The positive electrode is ultrasonically welded to the uncoated portion with a tab material made of aluminum having a length of 7 cm, a width of 1 cm, and a thickness of 0.01 cm, thereby producing a measurement electrode. The negative electrode is ultrasonically welded to the uncoated portion with a tab material made of nickel having a length of 7 cm, a width of 1 cm, and a thickness of 0.01 cm, thereby producing a measurement electrode. As measurement electrodes, 10 sets of positive electrodes and 11 sets of negative electrodes were prepared and dried at 160 ° C. for 40 minutes. Using a cellulose / rayon mixed nonwoven fabric having a thickness of 35 μm as a separator, the terminal welds of the positive electrode current collector and the negative electrode current collector are arranged on opposite sides, and the opposing surfaces of the positive electrode and the negative electrode are 20 layers. In addition, lamination is performed so that the outermost electrode of the laminated electrodes becomes a negative electrode. The uppermost part and the lowermost part are provided with separators, and four sides are taped, and the terminal welded part (10 sheets) of the positive electrode current collector and the terminal welded part (11 sheets) of the negative electrode current collector are ultrasonically welded.

  As a lithium electrode, a lithium metal foil (thickness 82 μm, length 5 cm × width 5 cm) bonded to an 80 μm-thick stainless steel mesh is used, and the lithium electrode is laminated so as to completely face the outermost negative electrode One sheet is placed at the top and one at the bottom. The terminal welding part (two sheets) of the lithium electrode current collector is resistance-welded to the negative electrode terminal welding part.

Laminate with the lithium foil placed at the top and bottom is placed inside the deep-drawn lower exterior film, covered with the exterior laminate film and fused on the three sides, and then ethylene carbonate, diethyl carbonate and propylene carbonate are used as the electrolyte. A solution obtained by dissolving LiPF ₆ at a concentration of 1 mol / liter is vacuum impregnated in a mixed solvent having a weight ratio of 3: 4: 1, and then the remaining one side is fused to produce a film type capacitor. The obtained hybrid capacitor has a capacitance density of 40 F / cc and a volume resistivity of 30 Ω · cm. The results are shown in Table 2.

(Comparative Example 2)
(Manufacture of positive electrode for hybrid capacitor)
In the same manner as in Comparative Example 1, a double-sided electrode having a conductive adhesive layer and an electrode active material layer on both sides of an aluminum punching metal (opening ratio 50%, manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.) having a thickness of 30 μm is prepared. . This is used as the positive electrode of the hybrid capacitor electrode.

(Manufacture of negative electrode for hybrid capacitors)
The slurry-like electrode composition obtained in Example 6 was applied to both sides of a copper punched metal having a thickness of 20 μm at a speed of 2 m / min using a roll coater, and then dried in a drying furnace, A double-sided electrode having an electrode active material layer having a thickness of 25 μm on one side is prepared on both sides of the body. This double-sided electrode is used as the negative electrode for the hybrid ion capacitor electrode. The thickness accuracy of the electrode active material layer of the obtained electrode is within 4%.

  In Example 6, a hybrid capacitor was fabricated in the same manner as in Example 6 except that the electrochemical element electrode was used as the electrochemical element electrode.

The obtained hybrid capacitor has a capacitance density of 40 F / cc and a volume resistivity of 35 Ω · cm. The results are shown in Table 2.

From the results of Examples and Comparative Examples, the following can be understood.
According to the present invention, by using an electrode active material sheet with a support having an electrode active material layer and a conductive adhesive layer in this order on the surface of the support, it can be easily formed on a perforated current collector, In addition, the electrode active material layer can be formed uniformly. Among the examples, those having a roughened surface as a support and having a roughened surface with a surface roughness Ra of 0.4 μm (Examples 2 and 6) were transferred. It is particularly excellent in the rate and the thickness accuracy of the electrode active material layer.

Claims (9)

On the support surface,
An electrode active material layer containing binder A and an electrode active material, and
A conductive adhesive layer comprising binder B and conductive particles,
Ri Na have in this order,
The conductive adhesive layer is formed by drying a slurry-like conductive adhesive composition containing the binder B and conductive particles.
Electrode active material sheet with support. The support has a roughened surface, and the roughened surface faces the electrode active material layer,
The electrode active material sheet with a support according to claim 1, wherein the surface roughness Ra of the roughened surface is 0.1 to 5 μm.   The electrode active material sheet with a support according to claim 1, wherein a surface of the support facing the electrode active material layer is subjected to a release treatment.   The electrode active material sheet with a support according to claim 3, wherein a contact angle with water on a surface of the support that has been subjected to a release treatment is 80 ° to 120 °. A step of forming an electrode active material layer comprising an electrode active material and a binder A on the support surface; and
Applying a slurry-like conductive adhesive composition comprising binder B and conductive particles on the electrode active material layer, and forming a conductive adhesive layer by drying;
The manufacturing method of the electrode active material sheet with a support body containing this. A step of bonding the electrode active material sheet with a support according to any one of claims 1 to 4 to a current collector, and
The manufacturing method of the electrode for electrochemical elements including the process of isolate | separating a support body from the electrode active material sheet with a support body bonded together to the electrical power collector. The method for producing an electrode for an electrochemical element according to claim 6 , wherein the current collector is a current collector having a through hole.   An electrochemical element comprising an electrode for an electrochemical element obtained by the production method according to claim 6.   The electrochemical device according to claim 8, wherein the electrochemical device is a hybrid capacitor.

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