JP2012169311A - Collector for electric double layer capacitor, electrode for electric double layer capacitor and manufacturing method therefor - Google Patents

Abstract

A current collector for suppressing a short circuit of a capacitor for an electric double layer caused by a porous aluminum sintered body breaking through a separator, and an electrode for increasing the density of a polarizable electrode material in the aluminum porous sintered body I will provide a.
An aluminum porous sintered body having a metal skeleton having a three-dimensional network structure, having pores between the metal skeletons, and having a pore diameter of 10 to 1000 μm between the skeletons; The pores contain a polarizable electrode material and a binder 3, and on one or both sides of the porous aluminum sintered body, an insulator layer 2 having a thickness of 0.01 to 100 μm, a polymer gel electrolyte layer, or a solid An electrical double layer capacitor current collector and an electrode, wherein an electrolyte layer is formed.
[Selection] Figure 3

Description

  TECHNICAL FIELD The present invention relates to a current collector for an electric double layer capacitor, an electrode for an electric double layer capacitor, and a method for producing the same, and in particular, a current collector for an electric double layer capacitor using an aluminum porous sintered body, The present invention relates to a multilayer capacitor electrode and a method of manufacturing the same.

  In recent years, non-aqueous electrolyte secondary batteries such as electric double layer capacitors, lithium ion batteries, and lithium ion polymer batteries have come to be used in electric vehicles, hybrid vehicles, etc. The electrode current collector in a battery is required to cope with high output and high energy density. Currently, an aluminum foil is generally used as an electrode current collector of these batteries, but an aluminum porous body having open pores having a three-dimensional network structure is becoming known as an electrode current collector ( Patent Documents 1 and 2).

  As an aluminum porous body, a non-pressure sintering high-strength aluminum porous sintered body using a sintering aid containing titanium has been reported (Patent Documents 3 and 4). This porous aluminum sintered body has a metal skeleton having a three-dimensional network structure, and has pores between the metal skeletons. Therefore, the aluminum porous sintered body is very suitable as a current collector for an electric double layer capacitor.

  However, as the density of the electric double layer capacitor increases, the amount of electrodes filled per unit volume of the electric double layer capacitor increases, and the aluminum porous sintered body, which is a current collector, breaks through the separator. There is a possibility that the multilayer capacitor is short-circuited.

  Further, after the aluminum porous sintered body is filled with a slurry containing a polarizable electrode material or a binder (hereinafter referred to as an electrode slurry) and before or after drying, the density of the polarizable electrode material is increased. Before the pressing, the polarizable electrode material may fall off from the surface of the aluminum porous sintered body, which may reduce the density of the polarizable electrode material in the aluminum porous sintered body.

Japanese Patent No. 3591055 Japanese Patent No. 3689948 JP 2010-255089 A JP 2010-236082 A

  The present invention suppresses the short circuit of the electric double layer capacitor caused by the aluminum porous sintered body breaking through the separator, and further increases the density of the polarizable electrode material in the aluminum porous sintered body. Is an issue.

The present invention relates to a current collector for an electric double layer capacitor, an electrode for an electric double layer capacitor, and a method for manufacturing the same, which have solved the above problems with the following configuration.
(1) A porous aluminum sintered body having a metal skeleton having a three-dimensional network structure, having pores between the metal skeletons, and having a pore diameter of 10 to 1000 μm, and the aluminum For an electric double layer type capacitor, characterized in that an insulator layer, a polymer gel electrolyte layer or a solid electrolyte layer having a thickness of 0.01 to 100 μm is formed on one side or both sides of a porous sintered body Current collector.
(2) A porous aluminum sintered body having a metal skeleton having a three-dimensional network structure, having pores between the metal skeletons, and having a pore diameter of 10 to 1000 μm between the skeletons, and the aluminum An insulating layer having a thickness of 0.01 to 100 μm and a polymer gel electrolyte on one or both sides of the aluminum porous sintered body, comprising a polarizable electrode material and a binder in the pores of the porous sintered body An electrode for an electric double layer capacitor, wherein a layer or a solid electrolyte layer is formed.
(3) The above-mentioned (2), wherein the binder is either an organic solvent-based binder or an aqueous binder, and the insulator layer, polymer gel electrolyte layer, or solid electrolyte layer is the other of the organic solvent-based binder or aqueous binder. The electrode for electric double layer type capacitors described in the above).
(4) An electrode for an electric double layer capacitor, wherein the insulator layer, the polymer gel electrolyte layer or the solid electrolyte layer contains a polarizable electrode material and / or a conductive additive.
(5) The electric double layer capacitor current collector is filled with a slurry containing a polarizable electrode material and a binder in the pores of the electric double layer capacitor current collector described in (1) and dried. A method for producing an electrode for an electric double layer capacitor, comprising rolling or pressing the electrode.
(6) In a porous aluminum sintered body having a metal skeleton having a three-dimensional network structure, having pores between the metal skeletons, and having a pore diameter of 10 to 1000 μm. Then, after filling a slurry containing a polarizable electrode material and a binder and drying, the aluminum porous sintered body is rolled or pressed, and an insulator layer, a high A method for producing an electrode for an electric double layer capacitor, comprising forming a molecular gel electrolyte layer or a solid electrolyte layer.
(7) The binder is one of an organic solvent-based binder or an aqueous binder, and the insulator layer, the polymer gel electrolyte layer, or the solid electrolyte layer is the other of the organic solvent-based binder or the aqueous binder, (5 ) Or the method for producing an electrode for an electric double layer capacitor according to (6).
(8) An electric double layer capacitor including the electrode for an electric double layer capacitor according to any one of (2) to (4).

  According to the present invention (1), the short circuit of the capacitor for the electric double layer due to the aluminum porous sintered body breaking through the separator can be suppressed, and further the density of the polarizable electrode material in the aluminum porous sintered body It is possible to provide an electrode for an electric double layer type capacitor having a high value.

  According to the present invention (2), it is possible to easily provide an electric double layer capacitor in which a short circuit due to the aluminum porous sintered body breaking through the separator is suppressed and the energy density is high.

  According to the present invention (6), the short circuit of the capacitor for the electric double layer caused by the aluminum porous sintered body breaking through the separator can be suppressed, and further the density of the polarizable electrode material in the aluminum porous sintered body It is possible to easily manufacture an electrode for an electric double layer capacitor having a high value.

It is a scanning electron micrograph of the aluminum porous sintered compact of an Example. It is a figure which shows an example of sectional drawing of the electrical power collector for electric double layer type | mold capacitors. It is a figure which shows an example of the manufacturing method of the electrode for electric double layer type capacitors of this invention. It is a figure which shows an example of the manufacturing method of the electrode for electric double layer type capacitors of another this invention. It is a figure which shows the shape of an aluminum sheet porous sintered compact. It is a figure which shows the shape of the electrical power collector for electrical double layer capacitors. It is a figure which shows the shape of the electrode precursor for electric double layer capacitors. It is a figure which shows the shape of the electrode for electrical double layer capacitors. It is a figure which shows the shape of the electrode for electrical double layer capacitors. It is a figure which shows the shape of the electrode for electrical double layer capacitors. It is a schematic diagram of the cell used for the short circuit evaluation of the electrode for electric double layer capacitors.

  Hereinafter, the present invention will be specifically described based on embodiments. Unless otherwise indicated,% is based on mass unless otherwise specified.

[Electric double layer capacitor current collector]
The current collector for the electric double layer capacitor of the present invention has a metal skeleton having a three-dimensional network structure, and has pores between the metal skeletons, and the pore diameter of the inter-frame vacancies is 10 to 1000 μm. An aluminum porous sintered body and an insulator layer, a polymer gel electrolyte layer, or a solid electrolyte layer having a thickness of 0.01 to 100 μm are formed on one surface or both surfaces of the aluminum porous sintered body. It is characterized by. Here, for the hole diameter, six scanning electron micrographs (50 ×, 100 mm × 150 mm) of the surface and cross section of the sample were prepared, and the cross sectional area of each hole included in the photograph was obtained. The equivalent diameter was calculated and taken as the average value. When calculating the equivalent diameter, it was assumed that the cross section of the hole was a circle.

  The aluminum porous sintered body has a metal skeleton having a three-dimensional network structure, has pores between the metal skeletons, and has a pore diameter of 10 to 1000 μm. As is apparent from FIG. 1, the porous aluminum sintered body forms pores by a metal skeleton having a three-dimensional network structure. In addition, the metal skeleton itself has a feature of high porosity.

  From the viewpoint of filling a desired amount of polarizable electrode material, the pore diameter of interstitial pores is 10 to 1000 μm, and preferably 30 to 600 μm. If the pore diameter is too small, the filling property of the slurry containing the polarizable electrode material and the binder (hereinafter referred to as polarizable electrode material slurry) deteriorates. If the pore diameter is too large, the current collecting performance decreases. The electric resistance of the electric double layer capacitor electrode will increase. Here, the pore diameter is measured by scanning electron micrographs of the surface and cross section of the sample. In addition, after rolling or pressing, the pore diameter of interstitial pores is an elliptical shape in which the longitudinal direction of the aluminum porous sintered body is long, and the pore diameter in the longitudinal direction is preferably 30 to 700 μm, and the thickness direction The pore diameter is preferably 10 to 400 μm.

  In order to obtain the desired aluminum porous sintered body strength, pore diameter, and porosity, the metal skeleton of the aluminum porous sintered body has a metal skeleton diameter (the thickness of the thinnest part of each metal bone forming the metal skeleton). Is preferably 5 to 100 μm. The metal skeleton preferably has skeleton vacancies having a pore diameter of 0.1 to 3 μm. Here, the metal skeleton diameter is measured by scanning electron micrographs of the skeleton surface and the skeleton cross section.

  The interstitial vacancies are preferably in communication from the viewpoint of easily including a polarizable electrode material, a binder, and the like, and ensuring good conductivity with the electrolyte.

  The total porosity of the aluminum porous sintered body is preferably 70 to 98%, more preferably 80 to 97%, from the viewpoint of filling a desired amount of polarizable electrode material. If the porosity is low, the capacity of the electric double layer capacitor electrode decreases, and if the porosity is too high, the current collection performance decreases due to a decrease in the specific surface area of the aluminum porous sintered body. The strength of the aluminum porous sintered body may be reduced, and the aluminum porous sintered body skeleton may be ruptured during consolidation by rolling or pressing, which may increase the electric resistance of the electric double layer capacitor electrode. In addition, the porosity after rolling is preferably 40 to 96%, and more preferably 80 to 94%. Here, the porosity is calculated by calculating the density from the size and mass of the aluminum porous sintered body and by calculating the ratio to the density of the bulk body having the same size.

  The metal skeleton is preferably formed of a sintered body obtained by non-pressure sintering of aluminum particles having a particle size of 4 to 40 μm. Here, the particle diameter is measured three times by a laser diffraction method and is an average value thereof.

  The aluminum porous sintered body preferably contains an Al—Ti compound in the metal skeleton from the viewpoint of increasing the strength of the aluminum porous sintered body and ease of production. The Al—Ti compound having a metal skeleton is derived from titanium contained in a sintering aid used when producing an aluminum porous sintered body. Titanium not only makes it possible to produce an aluminum porous sintered body by pressureless sintering, but also makes the aluminum porous sintered body high strength, especially high tensile, by forming an Al-Ti compound. Make it strong.

  The aluminum porous sintered body preferably contains 0.1 to 20 parts by mass of titanium with respect to 100 parts by mass of aluminum and titanium in total. If titanium is less than 0.1 part by mass, a good aluminum porous sintered body cannot be obtained. If it exceeds 20 parts by mass, sintering aid powder containing titanium in the aluminum mixed raw material powder at the time of sintering. They come to have contacts, making it impossible to control the reaction heat between aluminum and titanium, and making it impossible to obtain a desired porous sintered body. Here, the quantitative analysis of aluminum and titanium is performed by the ICP method.

  The thickness of the aluminum porous sintered body is preferably 0.05 to 5 mm before rolling and more preferably 0.2 to 3.0 mm from the viewpoint of improving the energy density of the electric double layer capacitor. . The thickness of the aluminum porous sintered body is preferably 0.03 to 3 mm after rolling or pressing, and more preferably 0.1 to 2.0 mm.

  The width of the aluminum porous sintered body is generally determined from the shape of the electric double layer type capacitor, but an aluminum porous sintered body is produced with a width corresponding to a plurality of widths. After forming an insulator, a polymer gel electrolyte, or a solid electrolyte on one or both sides of the metal, a polarizable electrode material or the like is contained in the pores of the aluminum porous sintered body, rolled, and then separated by a slit or the like. The width can also be

  Since the aluminum porous sintered body is usually produced in a roll shape, the length of the aluminum porous sintered body is usually produced by a length corresponding to many pieces, and one side of the aluminum porous sintered body or After forming an insulator, a polymer gel electrolyte, or a solid electrolyte on both surfaces, a polarizable electrode material or the like is contained in the pores of the aluminum porous sintered body, rolled, Is done.

  In the current collector for electric double layer capacitor of the present invention, an insulator layer, a polymer gel electrolyte layer or a solid electrolyte layer having a thickness of 0.01 to 100 μm is formed on one side or both sides of an aluminum porous sintered body. Has been. If the thickness of the insulator layer, polymer gel electrolyte layer or solid electrolyte layer is too thin, the insulator layer, polymer gel electrolyte layer or solid electrolyte layer cannot obtain the desired strength, and if it is too thick, the electric double layer The electrical resistance of the capacitor electrode increases.

  As an insulator layer formed on one or both sides of an aluminum porous sintered body, it is necessary not to dissolve in a non-aqueous electrolyte, and it is used as a binder for an active material, or used as a separator And silica. The type of the active material binder will be described in detail later, and examples thereof include water-soluble binders and organic solvent-based binders. As the insulating layer, organic solvent-based binders are preferable, and among these, polarizable electrode materials have a large binding force Although what disperse | distributed polyvinylidene fluoride (PVdF) in N-methyl 2 pyrrolidone (NMP) is more preferable, it is not limited to this. Examples of suitable materials for the separator include thermoplastic resins such as polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride resins, polystyrene, polyvinyl acetate, ethylene-vinyl acetate copolymers, and ethylene-vinyl chloride copolymers. Resin, low molecular weight polyethylene, low molecular weight polypropylene, copolymers thereof, synthetic wax such as microcrystalline wax, polyethylene wax, oxidized polyethylene wax or mixtures thereof, natural wax such as carnauba wax or derivatives thereof or mixtures thereof. Can be mentioned. Examples of silica include silica gel and colloidal silica. The insulator layer may contain a polarizable electrode material and / or a conductive aid. If the insulator layer contains a polarizable electrode material or a conductive additive, the insulator layer can be made conductive, but the presence of the insulator layer prevents the porous aluminum sintered body from breaking through the separator. Therefore, even if a polarizable electrode material or a conductive additive is contained in the insulator layer, the effect of the present invention is not impaired.

  The polymer gel electrolyte layer formed on one side or both sides of the aluminum porous sintered body is not particularly limited, but the electrolyte polymer having an ionic conductivity contains an electrolytic solution, and has no ionic conductivity. The thing etc. which hold | maintained the same electrolyte solution in the frame | skeleton of the polymer for electrolytes are mentioned. Here, as the electrolyte polymer having ion conductivity, a polymer solid electrolyte described later is used.

  Examples of the electrolyte polymer having no ion conductivity include polyvinylidene fluoride (PVdF), polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) copolymer, polyvinyl chloride (PVC), and polyacrylonitrile (PAN). ), Monomers that form gelling polymers such as polymethyl methacrylate (PMMA) can be used. However, it is not necessarily limited to these. Note that PAN, PMMA, etc. are in a class that has almost no ionic conductivity, and therefore can be used as an electrolyte polymer having the above ionic conductivity. It was exemplified as a polymer for electrolyte that does not have ionic conductivity.

The electrolytic solution contained in the polymer gel electrolyte includes an electrolyte salt, cyclic carbonates such as propylene carbonate (PC) and ethylene carbonate (EC); chain carbonates such as dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate; Ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-dibutoxyethane; lactones such as γ-butyrolactone; nitriles such as acetonitrile; methyl propionate, etc. Esters of amides such as dimethylformamide; those using an organic solvent (plasticizer) such as an aprotic solvent mixed with at least one selected from methyl acetate and methyl formate It is done. As the electrolyte salt, LiBOB (lithium bis oxide _{borate), LiPF 6, LiBF 4,} LiClO 4, LiAsF 6, LiTaF 6, LiAlCl 4, Li 2 B 10 Cl 10 inorganic acid anion salts such _{as, (C} 2 _{H 5} ) ₄ NBF ₄ , (C ₂ H ₅ ) ₃ CH ₃ NBF ₄ , (C ₂ H ₅ ) ₄ NPF ₆ , (C ₂ H ₅ ) ₃ CH ₃ NPF ₆ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, at least one electrolyte salt selected from organic acid anion salts such as Li (C ₂ F ₅ SO ₂ ) ₂ N.

  The ratio (mass ratio) between the electrolyte polymer (host polymer) and the electrolyte solution in the polymer gel electrolyte may be determined according to the purpose of use, but is in the range of 2:98 to 90:10. Thereby, it can seal effectively also about the oozing-out of the electrolyte from the outer peripheral part of the electrode for electric double layer type | mold capacitors by providing an insulating layer and an insulation process part. The polymer gel electrolyte layer may contain a polarizable electrode material and / or a conductive aid.

The solid electrolyte layer formed on one or both sides of the aluminum porous sintered body is not particularly limited as long as it has ion conductivity. For example, if the solid electrolyte of an inorganic, Chiorishikon and _Li 4 _SiO 4 _{-Li 3} BO 3 or _{LiX-Li 2 O-M m} O n (X = I, Br, Cl; M = B, Si, P , etc. , M and n are numbers from 1 to 5) and the like, and polymer-based solid electrolytes include polyethylene oxide (PEO), polypropylene oxide (PPO), A polymer etc. are mentioned. The polyalkylene oxide polymer exhibits excellent mechanical strength by dissolving the electrolyte salt well and forming a crosslinked structure. The electrolyte salt is as described above. The solid electrolyte layer may contain a polarizable electrode material and / or a conductive aid.

  In FIG. 2, an example of sectional drawing of the electrical power collector for electric double layer type capacitors of this invention is shown. An insulator layer 2 is formed on the surface of the aluminum porous sintered body 1. When the insulator layer is formed on the surface of the aluminum porous sintered body 1, as shown in FIG. 2, the insulator layer is formed on the end portion (outer surface) of the metal skeleton of the aluminum porous sintered body 1. 2 is preferably formed but not formed in the hole portion. In addition, it is preferable from the viewpoint of more reliably suppressing the dropping of the polarizable electrode material slurry if the insulator covers a part of the pores of the porous aluminum sintered body, but if the whole is covered, the movement of ions is hindered. It is not preferable.

  Further, when the polymer gel electrolyte layer or the solid electrolyte layer is formed on the surface of the aluminum porous sintered body, as shown in FIG. 2, the aluminum porous sintered body 1 is formed at the end of the metal skeleton. It is preferable from the viewpoint of easy movement of Li ions, but if the polymer gel electrolyte layer or the solid electrolyte layer covers a part or all of the pores of the aluminum porous sintered body, it is polarizable. This is preferable from the viewpoint of more reliably suppressing the electrode material slurry from falling off. Note that whether the insulator layer, the polymer gel electrolyte layer, or the solid electrolyte layer is formed on one side or both sides of the aluminum porous current collector can be appropriately selected depending on the structure of the electric double layer capacitor.

[Electric double layer capacitor electrode]
An electrode for an electric double layer capacitor of the present invention is an aluminum having a metal skeleton having a three-dimensional network structure, vacancies between the metal skeletons, and the vacancies of interframe vacancies are 10 to 1000 μm The porous sintered body includes a polarizable electrode material and a binder in the pores of the aluminum porous sintered body, and has a thickness of 0.01 to 100 μm on one or both sides of the aluminum porous sintered body. An insulating layer, a polymer gel electrolyte layer, or a solid electrolyte layer is formed.

  The aluminum porous sintered body, the insulator layer, the polymer gel electrolyte layer, and the solid electrolyte layer are as described above.

  Here, when the binder is one of an organic solvent-based binder or an aqueous binder, and the insulator, the polymer gel electrolyte, or the solid electrolyte is the other of the organic solvent-based binder or the water-based binder, the production is easy. It is preferable from the viewpoint. The binder will be described later.

  Examples of the polarizable electrode material contained in the pores of the porous aluminum sintered body include those used as polarizable electrode materials for electric double layer type capacitors, which can be polarized in an electrolyte. If there is, it will not be specifically limited. Conventionally, it is sufficient if it is generally used, and specifically, activated carbon having nano-sized pores is preferable. The polarizable electrode material is preferably a powder having an average particle diameter of 2 to 20 μm from the viewpoint of increasing the capacity of the electric double layer capacitor. Here, the average particle diameter is measured by a laser diffraction method.

  Examples of the binder contained together with the polarizable electrode material in the pores of the aluminum porous sintered body include an aqueous binder and an organic solvent binder. As the binder, a water-based binder is desirable from the viewpoint of drawing out the filling properties of the porous aluminum sintered body into the pores and maximizing the performance of the activated carbon itself. Examples of the aqueous binder include at least one selected from the group consisting of polytetrafluoroethylene, rubber binder, carboxymethyl cellulose salt, polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose, polyethylene oxide, and polyethylene glycol. Examples of the organic solvent-based binder include, but are not limited to, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), SBR, and polyimide.

  Aluminum porous sintered body: When 100 to 800 parts by mass of the polarizable electrode material is contained with respect to 100 parts by mass, it is preferable from the viewpoint of improving the energy density of the electric double layer capacitor, and more preferably 250 to 750 parts by mass. .

  Polarized electrode material: The binder is preferably contained in an amount of 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass. This is because when the amount of the binder is too small, the binding force of the polarizable electrode material cannot be obtained, and when the amount of the binder is too large, the blending ratio of the polarizable electrode material is reduced.

  In the present invention, the polarizable electrode material and the binder are contained in the pores of the aluminum porous sintered body, but also between the aluminum porous sintered body that is a current collector and the separator, Polarized electrode materials and binders can be included. In the present invention, the polarizable electrode material and the binder contained in the pores of the aluminum porous sintered body are 60 parts per 100 parts by mass of the polarizable electrode material and the binder in the electric double layer capacitor. It is preferable that it is -95 mass parts from a viewpoint of the improvement of the high energy density of an electric double layer type capacitor, and high output.

  Moreover, it is preferable from the viewpoint of high output that the pores of the aluminum porous sintered body further include a conductive additive. As the conductive aid, carbon-based, metal-based, and metal oxide-based materials can be used. Examples of carbon-based materials include carbon black (Ketjen black, furnace black, acetylene black), carbon whiskers, carbon fibers (carbon nanofibers, etc.), natural graphite, artificial graphite, and the like. Examples of metal oxides such as iron, silver, nickel, palladium, gold, platinum, indium, and tungsten include conductive particles such as indium oxide, tin oxide, and ruthenium oxide. Among these, ketjen black, acetylene black, and carbon nanofiber are preferable, but not limited thereto.

  Polarized electrode material: The conductive auxiliary agent is preferably contained in an amount of 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass. This is because if the amount of the conductive aid is too small, the electric resistance of the electric double layer capacitor electrode is increased, and if the amount is too large, the blending ratio of the polarizable electrode material is decreased.

  Examples of the electrolyte when using the electric double layer capacitor electrode of the present invention include an aqueous electrolyte and a non-aqueous electrolyte. From the viewpoint of withstanding voltage of the electrolyte and not dissolving the aluminum porous sintered body, the non-aqueous electrolyte is used. An electrolyte is preferred. The non-aqueous electrolyte may be either a liquid electrolyte (electrolytic solution) or a polymer gel electrolyte. The electrolyte solution is not particularly limited as long as it is used in a normal electric double layer type capacitor. The electrolytic solution and the polymer gel electrolyte are as described above.

[Method for producing current collector for electric double layer capacitor]

  An example of the method for producing an aluminum porous sintered body when titanium is used as a sintering aid will be described below.

  First, aluminum mixed raw material powder is prepared by mixing titanium powder and / or titanium hydride with aluminum powder to obtain an aluminum mixed raw material powder (aluminum mixed raw material powder preparation step). The aluminum mixed raw material powder is mixed with a water-soluble resin binder, water, and a plasticizer to prepare a viscous composition (viscous composition preparation step). This viscous composition is dried in a state where air bubbles are mixed to form a pre-sintered molded body (pre-sintering process), and the pre-sintered molded body is Tm-10 (° C.) ≦ heat-fired in a non-oxidizing atmosphere. It is heated and fired at a temperature (T) ≦ 685 (° C.) (sintering step). Here, Tm (° C.) is a temperature at which the aluminum mixed raw material powder starts to melt.

  In this aluminum mixed raw material powder preparation step, an aluminum powder having an average particle size of 2 to 200 μm is used. Here, when the average particle size is reduced, the aluminum powder is used in order that the viscous composition is so viscous that it can be formed into a desired shape, and that the pre-sintered compact has handling strength. A large amount of water-soluble resin binder must be added. However, if a large amount of the water-soluble resin binder is added, the amount of carbon remaining in the aluminum increases when the pre-sintered molded body is heated and fired, and the sintering reaction is hindered. On the other hand, when the particle diameter of the aluminum powder is too large, the strength of the aluminum porous sintered body is lowered. Therefore, as the aluminum powder, those having an average particle diameter in the range of 2 to 200 μm, more preferably 4 to 40 μm, and still more preferably 7 to 40 μm are used as described above. Here, the average particle diameter is measured by a laser diffraction method.

This aluminum powder is mixed with a sintering aid containing titanium, specifically, titanium and / or titanium hydride. Thereby, titanium is mixed with aluminum powder, and when the pre-sintered compact is heated and fired at Tm-10 (° C.) ≦ heating and firing temperature T ≦ 685 (° C.), a lump of droplets is generated. No pressureless sintering of aluminum is possible. Further, titanium hydride (TiH ₂ ) has a titanium content of 47.88 (molecular weight of titanium) / (47.88 + 1 (molecular weight of hydrogen) × 2) and is 95% by mass or more, and is 470 to 530 ° C. In order to dehydrogenate, it is thermally decomposed into titanium during the above-mentioned heating and firing. Therefore, even when titanium hydride is mixed, non-pressure-sintering of aluminum can be performed without generating droplet lumps. As the sintering aid, a sintering aid powder other than titanium or titanium hydride may be used, or a sintering aid powder containing titanium may be used.

  The sintering aid containing titanium preferably contains 0.1 to 20 parts by mass of titanium with respect to a total of 100 parts by mass of aluminum and titanium.

  Here, when the average particle diameter of titanium and / or titanium hydride is r (μm) and the blending ratio of titanium and / or titanium hydride is W (mass%), 1 (μm) ≦ r ≦ 30 ( μm), 0.1 (mass%) ≦ W ≦ 20 (mass%), and preferably 0.1 ≦ W / r ≦ 2. That is, in the case of titanium hydride powder having an average particle size of 4 μm, since 0.1 ≦ W / 4 ≦ 2, the compounding ratio W is preferably 0.4 to 8% by mass. In the case of titanium powder having an average particle diameter of 20 μm, the blending ratio: W is 2 to 40% by mass from the condition of 0.1 ≦ W / 20 ≦ 2, but the blending ratio: W is 0. .1 (mass%) ≦ W ≦ 20 (mass%) is added, and 2 to 20 mass% is preferable.

  The average particle size of titanium hydride is preferably 0.1 (μm) ≦ r ≦ 30 (μm), more preferably 4 (μm) ≦ r ≦ 20 (μm). If the average particle size of titanium hydride is smaller than 0.1 μm, there is a risk of spontaneous ignition, and if it exceeds 30 μm, the Al—Ti compound is formed from the titanium particles coated with the Al—Ti compound produced by sintering. This is because the phases are easily separated and desired strength cannot be obtained in the sintered body.

  Further, 0.1 (mass%) ≦ W ≦ 20 (mass%) is preferable because when the mixing ratio W of the sintering aid powder exceeds 20 mass%, the sintering aid powder in the aluminum mixed raw material powder. This is because they have contact points, making it impossible to control the reaction heat between aluminum and titanium, and making it impossible to obtain a desired porous sintered body. However, even within the range of 0.1 (mass%) ≤ W ≤ 20 (mass%), the reaction heat of aluminum and titanium may become too large depending on the particle size of the sintering aid powder, and it is dissolved by the reaction heat. In some cases, the temperature of the aluminum further rises to lower the viscosity and produce droplets. In order to prevent the generation of droplets, it is desirable that 1 (μm) ≦ r ≦ 30 (μm) and 0.1 ≦ W / r ≦ 2.

  Next, in the viscous composition preparation step, at least one selected from the group consisting of polyvinyl alcohol, methylcellulose and ethylcellulose as a water-soluble resin binder is added to the aluminum mixed raw material powder as a plasticizer, and polyethylene glycol, glycerin and phthalate as plasticizers. At least one selected from the group consisting of di-n-butyl acid is added, and distilled water and alkylbetaine or alkylbenzenesulfonate as a surfactant are added.

  As described above, when polyvinyl alcohol, methyl cellulose or ethyl cellulose is used as the water-soluble resin binder, the amount added is relatively small. Therefore, the addition amount of the water-soluble resin binder is 0.5 to 7 parts by mass with respect to 100 parts by mass of the aluminum mixed raw material powder. When the amount is more than 7 parts by mass with respect to 100 parts by mass of the aluminum mixed raw material powder, the sintering reaction is hindered by an increase in the amount of carbon remaining in the pre-sintered molded body before heating and firing, and 0.5 parts by mass. It is because the handling intensity | strength of the molded object before sintering is not ensured that it is less than.

  In addition, 0.02 to 3 parts by mass of the alkylbetaine or alkylbenzene sulfonate is added to 100 parts by mass of the aluminum mixed raw material powder. When the amount is 0.02 parts by mass or more with respect to 100 parts by mass of the aluminum mixed raw material powder, bubbles are effectively generated when the water-insoluble hydrocarbon organic solvent described later is mixed, and 3 parts by mass or less. In this case, inhibition of the sintering reaction due to an increase in the amount of carbon remaining in the green body before sintering is prevented.

  And after kneading | mixing these, it is made to foam by mixing a C5-C8 water-insoluble hydrocarbon-type organic solvent, and the viscous composition with which the bubble was mixed is adjusted. As the water-insoluble hydrocarbon organic solvent having 5 to 8 carbon atoms, at least one selected from the group consisting of pentane, hexane, heptane and octane can be used.

  In the next pre-sintering step, doctor blade method, slurry extrusion method, screen printing method, etc., so that the viscosity composition has a thickness of 0.05 mm to 5 mm on the stripping surface of the strip-shaped polyethylene sheet After the coating, the ambient temperature and humidity are controlled for a certain period of time, the air bubbles are sized, and then dried at a temperature of 70 ° C. with an air dryer.

  Then, the dried viscous composition is peeled off from the polyethylene terephthalate (PET) sheet, cut into a desired shape, and a pre-sintered shaped body is obtained.

  In the next sintering step, the pre-sintered compact is placed on an alumina setter and pre-baked by heating and holding at 520 ° C. for 1 hour in an argon atmosphere with a dew point of −20 ° C. or lower. This removes the binder that volatilizes and / or decomposes the binder solution of the water-soluble resin binder component, plasticizer component, distilled water and alkylbetaine of the green body before sintering, and also hydrogenates as a sintering aid powder. When titanium is used, dehydrogenation is performed.

  Thereafter, the pre-sintered compact after preliminary firing is fired at Tm-10 (° C.) ≦ heat firing temperature (T) ≦ 685 (° C.) to obtain an aluminum porous sintered body.

  Here, the pre-sintered compact is considered to start the reaction between aluminum and titanium when heated to Tm (° C.): 660 ° C., which is the melting temperature of aluminum. The melting point is lowered by the eutectic alloy elements such as Fe and Si contained, and in fact, the reaction between aluminum and titanium is started by heating at Tm-10 (° C.), and an aluminum porous sintered body is formed. Is done. Specifically, while the melting point of aluminum is 660 ° C., the atomization powder having a purity of about 98 to 99.7% circulating as pure aluminum powder has a melting start temperature of around 650 ° C. On the other hand, if the heating and firing temperature is maintained at a temperature higher than 685 ° C., aluminum droplet-like lumps are generated in the sintered body.

  In addition, in order to suppress the growth of the oxide film of the aluminum particle surface and the titanium particle surface, it is necessary to perform the heat baking in the sintering process in a non-oxidizing atmosphere. However, if the heating temperature is 400 ° C. or less and maintained for about 30 minutes, the oxide film on the aluminum particle surface and the titanium particle surface does not grow so much even when heated in air. After debinding by heating and holding at 300 to 400 ° C. for about 10 to 60 minutes in air, it may be fired at a predetermined temperature in an argon atmosphere.

  Here, the non-oxidizing atmosphere means an atmosphere that includes an inert atmosphere or a reducing atmosphere and does not oxidize the aluminum mixed raw material powder. In addition, the above-described heating and firing temperature is not the temperature of the aluminum mixed raw material powder, that is, does not measure the reaction temperature of the aluminum mixed raw material powder, but means the holding temperature around the aluminum mixed raw material powder. .

  The aluminum porous sintered body thus obtained has a metal skeleton with a three-dimensional network structure, has pores between the metal skeletons, and the Al-Ti compound is almost uniformly formed on the metal sintered body. Are dispersed. The aluminum porous sintered body is composed of pores derived from bubbles at the time of slurry foaming in the viscous composition preparation step, and pores formed in the metal skeleton itself derived from being a sintered body. It has two different types of holes.

  Next, a method of forming an insulator, a polymer gel electrolyte or a solid electrolyte (hereinafter referred to as “insulator etc.”) on the surface of the aluminum porous sintered body is achieved by adjusting the slurry of the insulator, etc. A method of coating on the surface of the porous sintered body and making it porous after film formation, a method of forming a film beforehand from an insulator, etc., laminating this on the surface of the aluminum porous sintered body, and making it porous, or insulating A method of forming a film such as a body on a substrate surface such as a release paper and transferring it to a surface of an aluminum porous sintered body in a dot pattern, a method of printing a slurry such as an insulator in a dot pattern by a printing method, etc. However, considering the adhesion between the aluminum porous sintered body surface and the insulator, a method of applying a slurry such as an insulator to make it porous is simple and preferable. If the viscosity of the slurry such as an insulator is low, a porous insulator or the like can be formed by bringing the aluminum porous sintered body surface into contact with the slurry of the coated thin film insulator or the like. . In addition, when forming a solid electrolyte in an aluminum porous sintered compact, a vapor deposition method etc. can also be used.

  Further, the slurry for forming the insulator or the like may contain a polarizable electrode material or a conductive additive. The blending ratio of the polarizable electrode material and the conductive additive is preferably about 0.1 to 30 parts by mass with respect to 100 parts by mass of the solvent in the slurry from the viewpoint of the viscosity of the slurry and the strength of the insulator. Here, examples of the solvent include water and organic solvents. Examples of the organic solvent include tetrahydrofuran (hereinafter referred to as THF), methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, N-methylpyrrolidone, acetone, acetonitrile, dimethyl carbonate, Examples include ethyl acetate and butyl acetate.

  As a method of making the insulator etc. porous, (1) using a thermal head or flash exposure etc., making a hole in the insulator etc. and making it porous, (2) using a melt transfer system, on the film After forming an insulator, etc., a method in which the insulator is melted and transferred in a dot pattern from the film side to the electrode plate surface with a thermal head or laser light, and (3) the insulator is made by screen printing. (4) Printing slurry such as insulator on the surface of the aluminum porous sintered body using a gravure roll. However, it is not limited to the above exemplified method.

[Method for producing electrode for electric double layer capacitor]
The method for producing an electrode for an electric double layer capacitor according to the present invention comprises filling the pores of the current collector for the electric double layer capacitor with a polarizable electrode material slurry, and drying it. The current collector is rolled or pressed.

  FIG. 3 is a diagram showing an example of a method for producing an electrode for an electric double layer capacitor of the present invention. First, as shown in FIG. 3A, the current collector for an electric double layer capacitor according to the present invention has a metal skeleton having a three-dimensional network structure, and has pores between the metal skeletons. An aluminum porous sintered body having a pore diameter of 10 to 1000 μm, an insulator having a thickness of 0.01 to 100 μm, and a polymer gel electrolyte on one or both surfaces of the aluminum porous sintered body Alternatively, a current collector for an electric double layer capacitor in which a solid electrolyte is formed is prepared.

  Next, as shown in FIG. 3 (B), the polarizable electrode material slurry is filled in the holes of the current collector for the electric double layer capacitor and dried. At this time, if the binder of the polarizable electrode material slurry is either an organic solvent binder or an aqueous binder, and the insulator is the other of the organic solvent binder or the aqueous binder, the polarizable electrode material slurry is filled. In this case, the insulator 2 formed on the surface of the aluminum porous sintered body 1 is preferable because it is difficult to dissolve in the solvent of the polarizable electrode material slurry.

  Thereafter, as shown in FIG. 3C, the current collector for the electric double layer capacitor is rolled or pressed. At this time, when the insulator 2 formed on the surface of the aluminum porous sintered body 1 is deformed and deformed like the insulator 2a, the holding power of the polarizable electrode material in the aluminum porous sintered body is increased. ,preferable. FIG. 3 shows an example in which the insulator 2 is formed on one surface of the porous aluminum sintered body. However, when a polymer gel electrolyte or a solid electrolyte is formed, the insulator 2 is replaced with the polymer gel electrolyte. Alternatively, it may be replaced with a solid electrolyte.

  Another method of manufacturing an electrode for an electric double layer capacitor according to the present invention has a metal skeleton having a three-dimensional network structure, has holes between the metal skeletons, and has a hole diameter of inter-frame holes. The pores of the aluminum porous sintered body having a thickness of 10 to 1000 μm are filled with a slurry containing a polarizable electrode material and a binder and dried, and then the aluminum porous sintered body is rolled or pressed. An insulator, a polymer gel electrolyte, or a solid electrolyte is formed on one side or both sides of the porous sintered body.

  FIG. 4 is a diagram showing an example of another method for producing an electrode for an electric double layer capacitor according to the present invention. First, as shown in FIG. 4 (A), the current collector for an electric double layer capacitor of the present invention has a metal skeleton having a three-dimensional network structure, and has vacancies between the metal skeletons. An aluminum porous sintered body 11 having a pore diameter of 10 to 1000 μm is prepared.

  Next, as shown in FIG. 4B, the pores of the electric double layer capacitor current collector are filled with a polarizable electrode material slurry and dried, and then the aluminum porous sintered body is rolled or pressed. To do.

  Thereafter, as shown in FIG. 4C, an insulator 12 is formed on the surface of the aluminum porous sintered body. At this time, if the binder of the polarizable electrode material slurry is either an organic solvent binder or an aqueous binder, and the insulator is the other of the organic solvent binder or the aqueous binder, the solvent in the insulator slurry In addition, the binder in the pores of the aluminum porous body is less likely to be dissolved, which is preferable. FIG. 4 shows an example in which the insulator 12 is formed on one surface of the aluminum porous sintered body. However, when the polymer gel electrolyte or the solid electrolyte is formed, the insulator 12 is replaced with the polymer gel electrolyte. Alternatively, it may be replaced with a solid electrolyte.

  The electrode for an electric double layer capacitor of the present invention has a metal skeleton having a three-dimensional network structure, and has pores between the metal skeletons, and the pore diameter of the inter-frame vacancies is 10 to 1000 μm. The pores of a certain aluminum porous sintered body are filled with a slurry containing a polarizable electrode material and a binder and dried, and further, the insulator, polymer gel electrolyte or The solid electrolyte can be formed and then manufactured by other manufacturing methods such as rolling or pressing the aluminum porous sintered body.

  Hereafter, each process of the manufacturing method of the electrode for electric double layer type capacitors of this invention is demonstrated.

  First, a process for producing a polarizable electrode material slurry will be described. The polarizable electrode material slurry can be obtained, for example, as follows. First, the binder is dissolved or uniformly dispersed in an organic solvent. This mixed solution and polarizable electrode material powder are mixed to form a slurry. Alternatively, after the polarizable electrode material and the binder are uniformly mixed, an organic solvent is added to form a slurry. At this time, the apparatus to be used may be those normally used by those skilled in the art, such as a planetary mixer, a ball mill, and a Henschel mixer. Here, the organic solvent has a viscosity that allows the slurry to be easily immersed in the aluminum porous sintered body in the step of immersing the next aluminum porous sintered body in the slurry, for example, 10 to 60 Pa · s. It is preferable to add.

  In addition, when the conductive additive is added to the slurry, the order of adding the conductive additive to the mixed solution is the same as the addition of the polarizable electrode material powder before and after the polarizable electrode material powder is mixed with the mixed solution. Either is acceptable.

  Examples of the organic solvent for dissolving or dispersing the binder include tetrahydrofuran (hereinafter referred to as THF), methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, N-methylpyrrolidone, acetone, acetonitrile, dimethyl carbonate, ethyl acetate, butyl acetate, and the like. Although it can be used, in order to selectively remove this organic solvent by drying, a volatile organic solvent having a boiling point of 100 ° C. or lower such as THF or acetone, or N-methylpyrrolidone having a high ability to dissolve a binder is preferable.

  Next, the process of filling the pores of the porous aluminum sintered body with the polarizable electrode material slurry and drying it will be described. Examples of the filling method include a method of dipping the aluminum porous sintered body into the polarizable electrode material slurry, a method of pouring the slurry from the upper part of the aluminum porous sintered body, and further passing between two rolls. It is possible to more effectively fill the pores of the porous aluminum sintered body with the polarizable electrode material by pushing the slurry of excess polarizable electrode material adhered to the surface by rubbing with a spatula. . Drying may be left in the air, or a dryer or the like may be used. After drying, measure the mass ratio between the porous aluminum sintered body and the polarizable electrode material and the binder. If the polar ratio of the polarizable electrode material and the binder is low, repeat the dipping and drying again. The desired amount can be obtained. On the other hand, when the mass ratio of the polarizable electrode material and the binder is high, the viscosity of the slurry can be lowered, and dipping and drying can be performed again to obtain a desired amount.

  Next, a process of rolling or pressing an aluminum porous sintered body containing a polarizable electrode material and a binder will be described. The aluminum porous sintered body can be rolled or pressed to a desired thickness, and the porosity of the electrode body can be reduced and the electrode density can be increased. Here, the electrode thickness is preferably 0.03 to 3 mm. Here, the density of the porous aluminum sintered body can also be increased by pressing, but rolling is preferred from the viewpoint of productivity.

  The method of forming an insulator or the like on the surface of an aluminum porous sintered body containing a polarizable electrode material and a binder is the above-described method for producing an aluminum current collector (including a polarizable electrode material and a binder in the pores) This is the same as the method of forming an insulator or the like on the surface of a non-aluminum porous sintered body.

  As described above, an electrode for an electric double layer capacitor can be manufactured. The electric double layer type capacitor including the electrode for the electric double layer type capacitor can suppress a short circuit of the electric double layer capacitor caused by the aluminum porous sintered body breaking through the separator, and further the aluminum porous sintered type. Since the density of the polarizable electrode material in the body is high, it has a high energy density and is very useful.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

[Production of current collector 1 for electric double layer capacitor]
The aluminum sheet porous sintered body is made of a commercially available average particle size: 15 μm aluminum powder (purity: 99% by mass or more) and average particle size: 10 μm titanium powder (purity: 99% by mass or more) in a mass of 95: 5. The mixture powder: 100 parts by mass with respect to the above mixed powder: 1 to 5 parts by mass of polyvinyl alcohol as a binder, 1 to 5 parts by mass of glycerin as a plasticizer, and alkylbenzene sulfonate as a surfactant : 0.1-3 parts by mass and heptane: 0.1-5 parts by weight as a foaming agent, and a total of 500 g together with 80 parts by mass of solvent water, and then kneaded to prepare a slurry. . The slurry was formed into a sheet by a doctor blade method, and further dried to obtain a sintered precursor by removing the solvent. This was degreased at 400 ° C. for 20 minutes in an argon gas flow environment, and then subjected to a firing treatment at 650 ° C. for 1 hour, whereby an aluminum sheet porous sintered body having a shape shown in FIG. Electrical body 1) was obtained. The obtained current collector 1 for an electric double layer capacitor had a thickness of 1.0 mm, a porosity of 70%, and an average pore diameter of about 10 μm.

[Preparation of current collector 2 for electric double layer capacitor]
In the method for producing the current collector 1 for the electric double layer capacitor, an aluminum porous sintered body was produced in the same manner except that the blending amount of the foaming agent was 1.5 times. The thickness was 1.0 mm, the porosity was 90%, and the average pore diameter was about 500 μm.

Next, the surface layer of the obtained porous aluminum sintered body contains 20 parts by mass of SiO ₂ fine particles having an average particle diameter of 0.1 μm by screen printing and 5 parts by mass of polytetrafluoroethylene as a solvent. N-methylpyrrolidone (NMP): 100 parts by mass was added to prepare a slurry, which was applied to the surface layer of the aluminum porous sintered body. This was vacuum-dried at 120 ° C. for 3 hours to obtain a current collector 2 for an electric double layer capacitor having a shape shown in FIG.

[Preparation of current collector 3 for electric double layer capacitor]
In the method for producing the current collector 1 for the electric double layer capacitor, an aluminum porous sintered body was produced in the same manner except that the amount of the foaming agent was 2.5 times. The thickness was 1.0 mm, the porosity was 90%, and the average pore diameter was about 1000 μm.

  Next, a slurry containing 100 parts by weight of N-methylpyrrolidone (NMP) as a solvent and 10 parts by weight of polyvinylidene fluoride (PVdF) as a solvent was prepared by screen printing, and the obtained porous aluminum sintered body was obtained. It was applied to the surface layer. This was vacuum dried at 120 ° C. for 3 hours to obtain a current collector 3 for an electric double layer capacitor having the same shape as that of the current collector 2.

[Production of current collector 4 for electric double layer capacitor]
An aluminum porous sintered body was produced by the same production method as that for the current collector 2 for an electric double layer capacitor. The thickness was 1.0 mm, the porosity was 90%, and the average pore diameter was about 500 μm.

  Next, a solid oxide powder of polyethylene oxide containing propylene carbonate electrolyte (average particle size 10 nm): 10 parts by weight and polyvinylidene fluoride (PVdF) by screen printing on the surface layer of the obtained porous aluminum sintered body : 5 parts by weight, N-methylpyrrolidone (NMP): 100 parts by weight as a solvent was added, and the slurry was applied. This was vacuum dried at 120 ° C. for 3 hours to obtain a current collector 4 for an electric double layer capacitor having the same shape as that of the current collector 2.

[Example 1]

[Preparation of electrode 1 for electric double layer capacitor]
An electrode 1 for an electric double layer capacitor was produced using the current collector 1. In addition, preparation of the electrode for electric double layer capacitors of an Example and a comparative example and the discharge capacity test of the electrode were performed in the dry room.

  First, water vapor activated activated carbon powder (average particle diameter of about 2 μm): 80 parts by weight, ketjen black (average particle diameter of 40 nm): 10 parts by weight, polytetrafluoroethylene (PTFE): 10 parts by weight, water of solvent: 80 A slurry was prepared by dispersing in parts by mass. The slurry was filled and vacuum-dried at 120 ° C. for 3 hours to obtain an electrode precursor for an electric double layer capacitor having a shape shown in FIG.

Next, the obtained electrode precursor for an electric double layer capacitor includes a polyethylene oxide solid electrolyte powder containing propylene carbonate electrolyte (average particle size 10 nm): 10 parts by weight and polyvinylidene fluoride (PVdF): 5 parts by weight Then, 100 parts by weight of N-methylpyrrolidone (NMP) was added as a solvent, and the slurry was applied. This was vacuum-dried at 120 ° C. for 3 hours, and fused while being pressed to obtain an electrode 1 for an electric double layer capacitor having a shape shown in FIG. 8 having a coating layer on the entire electrode surface. The thickness of the coating layer at this time was 0.1 μm. Moreover, the volume density of the activated carbon in the finally obtained electrode was 0.25 g / cm ³ . Table 1 shows manufacturing conditions and the like. In Table 1, the insulator layer and the electrolyte layer are described as a coating layer.

[Examples 2 and 3 and Comparative Examples 1 to 4]
Except having set it as the conditions of Table 1, it carried out similarly to Example 1, and performed Examples 2, 3 and Comparative Examples 1-4.

Example 4

[Preparation of electrode 2 for electric double layer capacitor]
An electric double layer capacitor electrode 2 was produced using the current collector 2.
First, steam activated activated carbon powder (average particle size of about 2 μm): 80 parts by weight, ketjen black (average particle size 40 nm): 10 parts by weight, polyvinylidene fluoride (PVdF): 10 parts by weight, N-methylpyrrolidone (NMP) ): Dispersed in 100 parts by weight of solvent to prepare slurry. The slurry was filled and vacuum-dried at 120 ° C. for 3 hours to obtain an electrode precursor for an electric double layer capacitor having a shape shown in FIG.

Next, the N-methylpyrrolidone (NMP) liquid is wiped to the obtained electrode precursor for the electric double layer capacitor by a spray method, and the coating layer on the surface of the current collector is gelled. It pressed in the state pinched | interposed into the PET film to which the coating process was performed, and this was vacuum-dried at 120 degreeC for 3 hours, and the electrode 2 for electric double layer capacitors of the shape shown in FIG. 10 was obtained. The thickness of the coating layer at this time was 10 μm. The volume density of the activated carbon in the finally obtained electrode was 0.34 g / cm ³ .

[Examples 5 and 6 and Comparative Examples 5 to 8]
Except having set it as the conditions of Table 1, it carried out similarly to Example 4, and performed Example 5, 6 and Comparative Examples 5-8.

Example 7

[Preparation of electrode 3 for electric double layer capacitor]
An electric double layer capacitor electrode 3 was produced using the current collector 3.
First, water vapor activated activated carbon powder (average particle diameter of about 2 μm): 80 parts by weight, ketjen black (average particle diameter of 40 nm): 10 parts by weight, polytetrafluoroethylene (PTFE): 10 parts by weight, solvent water: 80 A slurry was prepared by dispersing in parts by mass. The slurry was filled, vacuum dried at 120 ° C. for 3 hours, and then roll-pressed to obtain an electrode 3 for an electric double layer capacitor having a shape shown in FIG. 9 having a coating layer only on the surface of the current collector sheet. The volume density of the activated carbon at this time was 0.35 g / cm ³ . The thickness of the coating layer was 100 μm.

[Examples 8 and 9, and Comparative Examples 9 to 12]
Except having set it as the conditions of Table 1, it carried out similarly to Example 7, and performed Example 8, 9 and Comparative Examples 9-12.

Example 10

[Production of Electrode 4 for Electric Double Layer Capacitor]
An electric double layer capacitor electrode 4 was produced using the current collector 4.
Steam-activated activated carbon powder (average particle size: about 2 μm): 80 parts by weight, Ketjen black (average particle size: 40 nm): 10 parts by weight, polytetrafluoroethylene (PTFE): 10 parts by weight on the obtained current collector, Solvent water: dispersed in 80 parts by mass to prepare a slurry. The slurry was charged, vacuum dried at 120 ° C. for 3 hours, and then roll-pressed to form an electric double layer capacitor electrode 4 having the same shape as in Example 7 having a coating layer only on the surface of the current collector sheet. Obtained. The volume density of the activated carbon at this time was 0.34 g / cm ³ . The thickness of the coating layer was 10 μm.

[Examples 11 and 12, and Comparative Examples 13 to 16]
Except having set it as the conditions of Table 1, it carried out similarly to Example 10, and performed Examples 11 and 12 and Comparative Examples 13-16.

[Comparative Example 17]

[Preparation of electrode 5 for electric double layer capacitor]
A porous aluminum sheet obtained by the same production method as that for the current collector 1 for an electric double layer capacitor was prepared. The thickness was 1.0 mm, the porosity was 90%, and the average pore diameter was about 1000 μm.

Next, 80 parts by weight of water vapor activated activated carbon powder (average particle size of about 10 μm), 10 parts by weight of ketjen black (average particle size of 40 nm), and 10 parts by weight of polytetrafluoroethylene (PTFE) are dispersed in a solvent, and slurry Was made. The slurry was filled and vacuum dried at 120 ° C. for 3 hours to obtain an electrode precursor for an electric double layer capacitor. By subjecting this to a roll press, an electric double layer capacitor electrode having the shape shown in FIG. 7 was obtained. At this time, the volume density of the activated carbon was 0.22 g / cm ³ .

[Comparative Examples 18 and 19]
Comparative Examples 18 and 19 were performed in the same manner as Comparative Example 17 except that the conditions in Table 1 were used.

Example 13
The composition of the slurry applied to the electrode precursor for the electric double layer capacitor is as follows: solid oxide powder of polyethylene oxide containing propylene carbonate electrolyte (average particle size 10 nm): 10 parts by weight and polyvinylidene fluoride (PVdF): 5 parts by weight, Example 13 was carried out in the same manner as Example 1 except that water vapor activated activated carbon powder (average particle size: about 10 μm): 20 parts by weight and N-methylpyrrolidone (NMP): 120 parts by weight as solvent.

Example 14
In the manufacturing method of the current collector 2, the composition of the slurry applied to the surface layer of the aluminum porous sintered body is 20 parts by mass of SiO ₂ fine particles having an average particle size of 0.1 μm and 5 parts by mass of polytetrafluoroethylene: Steam activated carbon powder (average particle size: about 10 μm): 20 parts by weight, N-methylpyrrolidone (NMP) as a solvent: 120 parts by weight went.

Example 15
In the method for producing the current collector 3, the composition of the slurry applied to the surface layer of the porous aluminum sintered body is as follows: polyvinylidene fluoride (PVdF): 10 parts by weight, ketjen black (average particle size: 40 nm): 10 weights Example 15 was carried out in the same manner as in Example 7 except that N-methylpyrrolidone (NMP): 100 parts by weight was used.

Example 16
In the method for producing the current collector 3, the composition of the slurry applied to the surface layer of the aluminum porous sintered body is a solid oxide powder of polyethylene oxide containing propylene carbonate electrolyte (average particle size 10 nm): 10 parts by weight Example 10 except that polyvinylidene fluoride (PVdF): 5 parts by weight, Ketjen black (average particle size 40 nm): 10 parts by weight, N-methylpyrrolidone (NMP) as a solvent: 100 parts by weight Example 16 was conducted in the same manner.

Example 17
The composition of the slurry applied to the electrode precursor for the electric double layer capacitor is 5 parts by weight of a solid oxide powder of polyethylene oxide containing propylene carbonate electrolyte (average particle size 10 nm) and 5 parts by weight of polyvinylidene fluoride (PVdF). Steam activated activated carbon powder (average particle size: about 10 μm): 25 parts by weight, ketjen black (average particle size: 40 nm) 3 parts by weight, N-methylpyrrolidone (NMP) as solvent: 150 parts by weight Example 17 was carried out in the same manner as Example 1.

Example 18
In the method for producing the current collector 2, the composition of the slurry applied to the surface layer of the aluminum porous sintered body is as follows: SiO ₂ fine particles having an average particle size of 0.1 μm: 5 parts by mass and polytetrafluoroethylene: 5 parts by mass , Steam activated activated carbon powder (average particle size about 10 μm): 25 parts by weight, ketjen black (average particle size 40 nm): 3 parts by weight, N-methylpyrrolidone (NMP) as solvent: 150 parts by weight Example 18 was carried out in the same manner as in Example 4.

Example 19
In the method for producing the current collector 3, the composition of the slurry applied to the surface layer of the aluminum porous sintered body is as follows: polyvinylidene fluoride (PVdF): 5 parts by weight, water vapor activated activated carbon powder (average particle size: about 10 μm): Example 19 was performed in the same manner as in Example 7, except that 25 parts by weight, 3 parts by weight of ketjen black (average particle size 40 nm), and 120 parts by weight of N-methylpyrrolidone (NMP) as a solvent were used. .

Example 20
In the method for producing the current collector 3, the composition of the slurry applied to the surface layer of the aluminum porous sintered body is a solid oxide powder of polyethylene oxide containing propylene carbonate electrolyte (average particle size 10 nm): 10 parts by weight Polyvinylidene fluoride (PVdF): 5 parts by weight, water vapor activated activated carbon powder (average particle size about 10 μm): 25 parts by weight, ketjen black (average particle size 40 nm): 3 parts by weight, N-methylpyrrolidone as a solvent ( NMP): Example 20 was carried out in the same manner as in Example 10 except that the amount was 150 parts by weight.

<< Short-circuit evaluation between electrodes for electric double layer capacitor via separator >>
In FIG. 11, the schematic diagram of the cell used for the short circuit evaluation of the electrode for electric double layer capacitors is shown. The short-circuit evaluation between the electrodes for the electric double layer capacitor through the separator is performed by using the obtained electrode 101 and the separator 102 made of a cellulose porous film having a thickness of 40 μm, and the compression jig 105, the electrode 101, the separator in the compression test apparatus. 102, the electrode 101, and the compression jig 105 are laminated in this order and set as shown in FIG. 11. The two electrodes 101 thus set are connected to the leads 104 of the electrical resistance measuring device via the tab 103. It was.
The evaluation was performed by applying a pressure to the electrode in the direction of the broken line arrow in FIG. 11 and reaching 1 MPa, then applying a constant pressure of 1 MPa for 1 minute, and then unloading, and the electrical resistance value was The case where it changed in a pulse manner on the order of 1/10 or less in 1 second was defined as “with short circuit”, and the others were defined as “without short circuit”. When the test was carried out 10 times for each of the examples and comparative examples, the case where “short circuit occurred” three times or more was designated as “x”, and the case where the number was less than three was designated as “◯”. Table 1 shows the results.

《Electrode discharge capacity test》
First, two punched electrodes having a diameter of 15 mm were prepared, and a separator made of a circular cellulose porous membrane having a diameter of 18 mm and a thickness of 40 μm was sandwiched between the two electrodes. This was fitted into a stainless steel coin-type outer container (diameter: 20 mm, depth: 3.0 mm) with polypropylene packing, and after vacuum drying at 150 ° C. for 3 hours, the electrolyte solution (propylene carbonate solution ( C ₂ H ₅ ) ₄ PBF ₄ mixed at a rate of 1 mol / dm ³ ) was injected. This was covered with a battery cover via a polypropylene packing, fixed, and sealed, thereby producing a coin cell type electric double layer capacitor having a diameter of 20 mm and a height of about 3.2 mm. Next, the cell was discharged at a discharge rate of 1.0 C and a discharge voltage of 2.5 to 0 V. From the discharge capacity, the discharge capacity per unit activated carbon mass in the electrode for the electric double layer capacitor (Table 1 , "Discharge capacity per unit activated carbon mass"), the discharge capacity per unit volume of the electric double layer capacitor electrode (described as "discharge capacity per unit volume" in Table 1). Table 1 shows these results.

  As can be seen from Table 1, in all of Examples 1 to 20, the activated carbon volume density, the discharge capacity per unit active material mass, the discharge capacity per unit volume were high, and the result of short circuit evaluation was also “◯”. In particular, Examples 18 and 20 had remarkably high activated carbon density and discharge capacity per unit volume. On the other hand, in Comparative Examples 1, 5, 9, and 13 in which the pore diameter of the aluminum porous body is 5 μm, the activated carbon volume density is low, and accordingly, the discharge capacity per unit volume of the electrode for the electric double layer capacitor Was also low. This is because the pore diameter is too small. Further, in Comparative Examples 2, 6, 10, and 14 in which the pore diameter of the aluminum porous body was 1500 μm, the discharge capacity per unit active material was low. This is because if the pore diameter is too large, the current collecting performance is lowered. In Comparative Examples 3, 7, 11, and 15 having a coating layer of 0.005 μm, the short circuit evaluation was “x”. In Comparative Examples 4, 8, 12, and 16 having a coating layer of 200 μm, charging / discharging could not be performed. In all of Comparative Examples 17 to 19 having no coating layer, the short circuit evaluation was “x”.

  As described above, the electrode for the electric double layer capacitor of the present invention can suppress the short circuit of the capacitor for the electric double layer caused by the aluminum porous sintered body breaking through the separator, and further the aluminum porous sintered body. It was found that an electric double layer capacitor having a high density of the polarizable electrode material can be provided.

1, 11 Aluminum porous sintered body 2, 2a, 12 Insulator layer 3, 13 Polarized electrode material and binder 21, 31 Aluminum porous sintered body 32 Insulator layer 23, 33 Pore 41, 51, 61 , 71 Aluminum porous sintered body 52, 62, 72 Insulator layer 43, 53, 63, 73 Holes after slurry filling 101 Electrode for electric double layer capacitor 102 Separator 103 Tab 104 Lead 105 Compression jig

Claims (8)

  An aluminum porous sintered body having a metal skeleton having a three-dimensional network structure, having pores between the metal skeletons, and having a pore diameter of 10 to 1000 μm between the skeletons; An electric current collector for an electric double layer capacitor, wherein an insulator layer, a polymer gel electrolyte layer or a solid electrolyte layer having a thickness of 0.01 to 100 μm is formed on one side or both sides of the bonded body .   An aluminum porous sintered body having a metal skeleton having a three-dimensional network structure, having pores between the metal skeletons, and having a pore diameter of 10 to 1000 μm between the skeletons; A polarizable electrode material and a binder are contained in the pores of the bonded body, and an insulating layer, a polymer gel electrolyte layer, or a solid having a thickness of 0.01 to 100 μm is formed on one or both surfaces of the porous aluminum sintered body. An electrode for an electric double layer type capacitor, wherein an electrolyte layer is formed.   The binder is either an organic solvent-based binder or an aqueous binder, and the binder contained in the insulator layer, the polymer gel electrolyte layer, or the solid electrolyte layer is the other of the organic solvent-based binder or the aqueous binder. 3. The electrode for an electric double layer capacitor according to 2.   An electrode for an electric double layer capacitor, comprising a polarizable electrode material and / or a conductive aid in an insulator layer, a polymer gel electrolyte layer, or a solid electrolyte layer.   The electric double layer capacitor current collector according to claim 1 is filled with a slurry containing a polarizable electrode material and a binder, dried, and then rolled or pressed. Manufacturing method of electrode for multilayer capacitor.   It has polarizability in the pores of the porous aluminum sintered body having a metal skeleton having a three-dimensional network structure, having pores between the metal skeletons, and having a pore diameter of 10 to 1000 μm. After filling and drying a slurry containing an electrode material and a binder, the aluminum porous sintered body is rolled or pressed, and further, an insulator layer and a polymer gel electrolyte are formed on one or both sides of the aluminum porous sintered body. A method for producing an electrode for an electric double layer capacitor, comprising forming a layer or a solid electrolyte layer.   The binder is either an organic solvent-based binder or an aqueous binder, and the binder contained in the insulator layer, the polymer gel electrolyte layer, or the solid electrolyte layer is the other of the organic solvent-based binder or the aqueous binder. 7. A method for producing an electrode for an electric double layer capacitor according to 5 or 6.   The electric double layer type capacitor containing the electrode for electric double layer type capacitors of any one of Claims 2-4.