WO2014112337A1 - Dielectric material and electrochemical element using same - Google Patents

Abstract

The present invention provides: a dielectric material which enables the production of an electric double layer capacitor without requiring a costly and time-consuming production procedure; and a dielectric material which is capable of providing an electric double layer capacitor or the like having an electricity storage performance equal to or higher than that of a conventional electric double layer capacitor or the like. A dielectric material of the present invention is characterized by containing a reducing graphene oxide, an inorganic acid and/or a carbonic acid ester.

Description

Dielectric material and electrochemical device using the same

The present invention relates to a dielectric material, an electrochemical element using the dielectric material, a power storage device using the electrochemical element, and the like.

In recent years, low-emission vehicles such as electric vehicles and hybrid vehicles have been developed from the perspectives of mitigating air pollution in large cities by automobile exhaust gas, promoting the use of alternative energy for petroleum, and reducing carbon dioxide emissions that contribute to the prevention of global warming Popularization is required. In addition, with the introduction of distributed power sources based on natural energy such as solar power, wind power, and hydropower to power systems, various power storage devices are being developed. Development to increase the withstand voltage is underway. And as an electrochemical element used for a power storage device, for example, an electric double layer capacitor capable of high density and large capacity has attracted attention.

Since the capacity of the electric double layer capacitor is proportional to the surface area of the polarizable electrode, activated carbon having a large surface area is generally used as the material of the polarizable electrode. Activated carbon is produced by carbonizing raw materials having a high carbon content such as coconut husk, petroleum pitch, petroleum coke, etc. at a low temperature of 300 to 700 ° C. and then activating them. For the activation, for example, an inorganic acid such as water vapor, hydrochloric acid, nitric acid, sulfuric acid, or a potassium salt such as potassium hydroxide is used, which contributes to an increase in production cost.

Furthermore, in the conventional electric double layer capacitor, in order to increase the surface area of the polarizable electrode, the granulated activated carbon is uniformly dispersed in an electrolyte such as propylene carbonate. In practice, it is difficult to uniformly disperse the activated carbon in the electrolytic solution, and there is a problem that it is difficult to effectively utilize the surface area inherent to the activated carbon.

Therefore, a technique for increasing the capacity by using carbon nanotubes instead of activated carbon as a material constituting the polarizable electrode and arranging the carbon nanotubes one by one in the same direction has attracted attention.

For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-266548), there is no risk of leakage due to deformation caused by impact or bending load, and the electric double layer is thin and can store a large amount of electricity. In order to provide a capacitor, “a pair of positive and negative electrodes formed by forming a gel electrolyte membrane on a current collector so as to cover a group of carbon nanotubes provided on the current collector, There has been proposed an “electric double layer capacitor using carbon nanotubes”, characterized in that the carbon nanotube group of the positive electrode and the carbon nanotube group of the negative electrode face each other and are arranged in a non-contact manner.

JP 2007-266548 A

However, as proposed in Patent Document 1 above, adopting a structure in which the carbon nanotube group of the positive electrode and the carbon nanotube group of the negative electrode face each other and are arranged in a non-contact manner is also in the manufacturing process. This is very cumbersome and results in an increase in the cost of the final product.

In addition, further improvement in electrical performance such as capacitance has been demanded due to the demand for large capacity storage devices.

Therefore, an object of the present invention is to provide a dielectric material (a material for a polarizable electrode) that can produce an electric double layer capacitor or the like without requiring a costly and laborious manufacturing process as in the case of using carbon nanotubes. Another object is to provide a dielectric material capable of realizing an electric double layer capacitor or the like having a storage performance equal to or higher than that of the conventional one.

As a result of intensive studies on various dielectric materials in order to achieve the above object, the present inventors have found that a specific carbon nanomaterial and an inorganic acid and / or Alternatively, the present inventors have found that it is extremely effective to use a dielectric material containing carbonate ester, and the present invention has been achieved.

That is, the present invention
Reduced graphene oxide,
Containing an inorganic acid and / or a carbonate ester,
A dielectric material is provided.

The dielectric material of the present invention may contain a lithium compound, and in the dielectric material of the present invention, the reduced graphene oxide has at least one substance selected from silver, copper, zinc oxide, and palladium. It is preferably intercalated and doped.

The present invention also provides:
A polarizable electrode comprising at least the above dielectric material of the present invention;
A separator;
Including a first collector electrode and a second collector electrode;
An electrochemical device is provided.

In the electrochemical device of the present invention, at least the dielectric material of the present invention is applied to the first collector electrode and / or the second collector electrode, and the applied dielectric material is dried, thereby the first collector electrode. It is preferable that the collector electrode and / or the second collector electrode are surface-treated.

The term “electrochemical element” as used herein is a concept including all elements that include the dielectric material of the present invention and whose electrical characteristics can be used chemically. For example, an electric double layer capacitor, a capacitor, A battery (including a secondary battery and a storage battery) and a device in which these are enlarged are also included in the “electrochemical element” of the present invention.

The present invention also provides:
Including the electrochemical device of the present invention as described above,
A power storage device is provided.

The term “power storage device” as used herein refers to electrical equipment used as a power supply source, such as an uninterruptible power supply device, an instantaneous voltage drop compensation device, and a backup power supply, and further, for example, automobiles, wind power generation devices, and solar power generation. It is a concept including a system for storing and effectively using electricity obtained from another power generation device such as a device.

If the electrochemical device of the present invention is used in the above-mentioned electrical equipment used as a power supply source, even when handling a DC high voltage, it is not necessary to connect a large number of capacitors in a multi-stage DC manner as in the past, and it is stable. It is possible to reduce the operation and the number of parts.

As for a system for storing and effectively using electricity obtained from other power generators, it is effective for storing power obtained from a power source for driving a motor or regenerative brake when used in an automobile. Can be used. In addition, the power generation system using wind power or sunlight generates natural power generation unevenness because it uses natural energy. By using the electrochemical element of the present invention, this power generation unevenness is eliminated, and the difference in supply and demand. It becomes relatively easy to fill the space, and the effective use of electricity becomes possible.

Furthermore, the present invention provides
Reduced graphene oxide,
Mixing with inorganic acid and / or carbonate ester,
A method for producing a dielectric material is provided.

In the method for producing a dielectric material according to the present invention, a lithium compound may be further mixed, and at least one substance selected from silver, copper, zinc oxide, and palladium is intercalated in the reduced graphene oxide. -It is preferable that it is doped.

According to the present invention, there is provided a dielectric material (a material for a polarizable electrode) capable of manufacturing an electric double layer capacitor or the like without requiring a costly and laborious manufacturing process as in the case of using carbon nanotubes. In addition, it is possible to provide a dielectric material having a high electrostatic capacity capable of realizing an electric double layer capacitor having a power storage performance equal to or higher than that of the conventional one.

It is a schematic block diagram of one Embodiment of the electrochemical element of this invention. It is a schematic block diagram of another embodiment (electric double layer capacitor) of the electrochemical element of this invention. It is the schematic perspective view which notched some other embodiment (lead storage battery) of the electrochemical element of this invention. It is a schematic sectional drawing of the electrochemical element for a measurement produced in order to measure the electrostatic capacitance of a dielectric material in the Example of this invention. It is the graph which showed the electrostatic capacitance of the dielectric material of this invention. It is a schematic sectional drawing of the electrochemical element for laminated | stacked measurement produced in order to measure the electrostatic capacitance of a dielectric material in the Example of this invention.

Hereinafter, representative embodiments of the dielectric material of the present invention and electrochemical devices using the same will be described in detail with reference to some drawings, but the present invention is not limited to these. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant description may be omitted. Further, since the drawings are for conceptually explaining the present invention, the dimensions and ratios of the components shown may be different from the actual ones.

≪Dielectric material≫
The dielectric material of the present invention is characterized by having reduced graphene oxide and an inorganic acid and / or carbonate ester. The dielectric material may be in the form of powder, granules, or agglomerates after a drying step and / or a firing step.

Reduced graphene oxide is a monomolecular film of graphite, and reduced graphene oxide produced by various conventionally known methods can be used as long as the effects of the present invention are not impaired.

Graphite has a layered structure in which hexagonal mesh plane layers (reduced graphene oxide) are laminated by van der Waals force. By defeating van der Waals force between graphite layers and peeling the graphite one by one, it is reduced. Type graphene oxide can be obtained.

In order to obtain reduced graphene oxide, a method is known in which graphite is mechanically peeled off with an adhesive tape. However, this method is low in reliability and large-scale reduced graphene oxide cannot be obtained because large-area reduced graphene oxide cannot be obtained. Is difficult. Therefore, recently, a method for oxidizing graphite has been performed.

That is, when a strong oxidizing agent such as potassium permanganate or sulfuric acid is allowed to act on graphite in water, carbon on the surface of each layer of graphite is oxidized, and substituents containing oxygen on the surface (carboxyl group, hydroxyl group, epoxide, etc.) Is obtained. Graphite oxide exhibits hydrophilicity due to the presence of these substituents, and peels when dispersed in water, whereby an aqueous dispersion of reduced-type graphene oxide oxide having a single layer is obtained. Furthermore, by sonication, the graphite oxide is more uniformly exfoliated into a single layer of graphite oxide and stably dispersed for a long period of time. Therefore, in this method, the graphite oxide can be easily produced at a low cost and in large quantities.

The graphite oxide is a single layer and has a large specific surface area. However, the π-electron conjugated network is divided by the introduced oxygen-containing substituent, and the electrical conductivity is reduced, resulting in an insulating state. Cannot be used. Here, electric conductivity can be recovered by reducing a substituent containing oxygen. For example, a chemical reduction method in which a reducing agent such as hydrazine is added in the presence of a base to a water dispersion in which graphite oxide is dispersed in water for reduction, and water dispersion in which graphite oxide is dispersed in water. There is a thermal reduction method or the like in which a water-miscible solvent such as n-methylpyrrolidone or ethylene glycol is added to the liquid, and the mixture is heated to about 200 ° C. for reduction.

Here, examples of the reduced graphene oxide that can be suitably used include “Graferrite RGO” manufactured by MICC Corporation. In addition, instead of reduced graphene oxide, reduced graphene oxide is obtained by intercalating and doping at least one substance selected from silver, copper, zinc oxide, and palladium. The capacity can be further improved. In addition, as what intercalated and doped silver, copper, zinc oxide, and palladium to reduced graphene oxide, “Graferrite ag007: Silver intercalated and doped” manufactured by MICC Corporation, “Graferrite” “Cu008: Intercalate doping of copper”, “Graferrite zn009: Intercalation doping of zinc oxide”, and “Graferrite Pd010: Intercalation doping of palladium” can be preferably used. “Graferrite RGO” manufactured by MICC TEC Co., Ltd. has a particle size of 4 to 80 μm, a thickness of 2 to 40 nm, and a linear shape.

Reduced graphene oxide can be obtained by reducing graphene oxide. Graphene oxide is produced as follows. First, graphite is sulfonated. This sulfonation reaction is carried out by using concentrated sulfuric acid and concentrated nitric acid as a medium, potassium permanganate as an oxidizing agent, and carbonized D-glucose cake as a sulfonation catalyst (Human Systems Co., Ltd., product name: carbonized D-glucose 569). ). In the sulfonation reaction, a container resistant to concentrated sulfuric acid and concentrated nitric acid, which are strong acids, for example, a borosilicate heat-resistant glass container is used.

Here, the graphite used in the reaction may be natural or synthetic, but a purity of 99% or more is preferable. Further, when natural graphite is used as the graphite source, it is preferable to use a product having a purity of 99% or more because impurities such as silica are present. The amount of graphite used is, for example, 1 to 50 g, preferably 10 to 30 g, per 100 ml of concentrated sulfuric acid.

Furthermore, when producing metal-doped reduced graphene oxide, a sulfonated reaction is carried out in the presence of a metal or a metal compound. As the metal, for example, various metals such as silver, palladium, copper, and zinc can be used. Moreover, as a metal, it can mix | blend with various forms, such as a metal oxide (zinc oxide etc.), a hydroxide, and a salt. The amount of the metal or compound thereof to be blended is suitably 0.01 to 5% by mass, preferably 0.1 to 3% by mass, for example, based on graphite.

The solid acid catalyst uses, for example, dehydration action or oxidation action such as concentrated sulfuric acid (eg 98%) or fuming sulfuric acid against carbon sources such as D-glucose, cellulose, naphthalene, and anthracene. Carbonized and sulfonated at a high temperature of about 200 to 300 ° C. Due to the sulphonation, the sulphonated graphite particles have an affinity for sulfuric acid, so that dispersibility due to submerged ablation can be further enhanced. The amount of the solid acid catalyst is, for example, 20 g of graphite, for example, carbonized D glucose compound (manufactured by Human Systems Co., Ltd., product name: carbonized D glucose 569) as the solid acid catalyst is, for example, 0.1 to It is suitable to use 10 g, preferably 0.5 to 5 g.

The sulfonation reaction can be performed by performing laser ablation in a liquid while stirring graphite with a magnetic stirrer. By the laser ablation in the liquid, the graphite particles in the reaction vessel can be refined into a nanocolloid state and suspended. Laser ablation in the liquid generates a strong pulse in the liquid for the graphite particles, thereby expanding the interlayer spacing of the graphite and the presence of the concentrated sulfuric acid, concentrated nitric acid, oxidant, and solid acid catalyst present. Due to the action, delamination and oxidation and sulfonation reactions can be performed.

The obtained sulfonated graphite particles are considered to exist in a state in which sulfonic acid groups enter between graphite layers and are bonded or added to a benzene ring. In addition, when a metal is doped, there is a high possibility that the metal exists as a form of intercalation incorporated between phases. Therefore, when the metal-doped reduced graphene oxide finally obtained is a capacitor, it is considered that the metal ions taken in and out function as a function of taking in and out charges.

Laser ablation is known per se and is used in water as a technique for producing a metal dispersion in which the surface of a material such as a metal is generally modified with a laser and uniformly dispersed in water in the form of nanocolloid particles and does not settle. It has come to be used. When a pulse laser in the visible region is used, ablation occurs in water, and a large pressure plume is formed on the surface of the material for a short time, and this pressure is used to locally deform the metal surface. It is understood. Underwater, the plume expansion is suppressed by the inertia of water, so the plume pressure is 10 to 100 times that in air, reaching several gigapascals (GPa). It is understood that this pressure generates shock waves and propagates through the material.

As a laser used for laser ablation, a YAG laser (wavelength, for example, 1.06 μm) that can be sent into a liquid by a glass fiber can be suitably used. By performing laser ablation in liquid under stirring in a liquid medium, the multilayer graphite interlayer distance is expanded by about 3 times, for example, and strong sulfonation conditions are present in the presence of a solid acid catalyst suitable for sulfonation. Thus, it becomes possible to introduce a sulfonic group into the benzene ring of graphite, and a nano-dispersed liquid of sulfonated graphite particles can be obtained.

The sulfonated graphite in the sulfonated graphite nanodispersion thus obtained is then hydrolyzed and converted to graphene oxide. The obtained sulfonated graphite particles can be hydrolyzed by adding water and hydrochloric acid.

The amount of water used is, for example, about 500 to 1200 ml, preferably about 700 to 900 ml with respect to 100 ml of concentrated sulfuric acid. The concentration of concentrated hydrochloric acid used is, for example, 25 to 40% by mass, and preferably 34 to 37% by mass. The amount of hydrochloric acid used is, for example, 5 to 20 g, preferably 8 to 12 g, based on 20 g of potassium permanganate. Residual potassium permanganate, carbonized D-glucose cake (manufactured by Human Systems Co., Ltd., product name: carbonized D-glucose 569) is allowed to cool naturally for about 5 to 60 minutes, preferably about 10 to 30 minutes after hydrolysis. Decomposes and raises impurities. The suspended impurities are removed, and the reaction product dispersed in the medium is separated into a solid phase and a liquid phase using a centrifugal separator. Next, the supernatant is discarded, and the paste-like solid phase can be made into solid graphene oxide powder by heat drying or adding 400 ml of water, lowering the viscosity, and removing water by a spray dryer or the like.

The formation of graphene oxide can be confirmed by a Raman spectrum. Similarly, the generation of metal-doped graphene oxide can be confirmed by a Raman spectrum.

The graphene oxide or metal-doped graphene oxide obtained as described above is then subjected to a gradual reduction, leaving a functional group such as a hydroxyl group or a carboxyl group, unlike graphene, unlike graphene. Metal-undoped or metal-doped reduced graphene oxide having a morphological structure is obtained.

Hereinafter, a process for producing metal-undoped or metal-doped reduced graphene oxide will be described. Preferably, the metal undoped graphene oxide or the metal doped graphene oxide powder introduced into the reactor heated by a heating device such as a mantle heater is reduced while flowing a nitrogen stream from a nitrogen cylinder. In this case, since the obtained metal undoped or metal doped reduced graphene oxide is very fine and bulky, in order to efficiently collect the obtained metal undoped or metal doped reduced graphene oxide, two traps are collected. A collecting device may be employed. As such a collecting device, a commercially available product can be used, and for example, a silent cleaner manufactured by Osawa & Company can be appropriately used.

In the case of using an inert gas, the flow rate of the inert gas can be employed without any particular limitation as long as the flow rate is such that reduction can be performed. For diversion, for example, it is generally 0.5 to 40 liters / minute (L / minute), preferably about 5 to 30 liters / minute. During the reaction, the metal-undoped graphene oxide or the metal-doped graphene oxide is transported to the inert gas while being reduced and moves to the collection device. The reduction temperature is generally 100 to 400 ° C., preferably 150 to 300 ° C. When this temperature reaches 1100 ° C., complete reduction occurs and graphene is formed.

The metal-undoped or metal-doped reduced graphene oxide obtained in this way is very dispersible in water and has completely different properties from graphene due to the hydrophilic action of the functional groups present inside. . For this reason, the difference in structure with graphene is clear. Unlike graphene, reduced graphene oxide is easily dispersed in water due to hydrophilic functional groups such as hydroxyl groups and carboxyl groups present in reduced graphene oxide. On the other hand, since graphene has no functional group, it can be dispersed only in a special and expensive lipophilic solvent. Further, the reduced graphene oxide can be confirmed to be different from the graphene oxide by the shift of the peak position from the Raman spectrum diagram.

The obtained reduced graphene oxide, particularly the metal-doped reduced graphene oxide, is intercalated between layers as a metal ion when the doped metal ion is a multilayered reduced graphene oxide. When used as a capacitor, it has an excellent function. In addition, even if it is a single layer, it is bonded to another layer by an ionic bond or the like through a functional group of the single layer. Can fulfill.

As the inorganic acid used in the present invention, various inorganic acids can be used as long as the effects of the present invention are not impaired. For example, concentrated sulfuric acid, dilute sulfuric acid, nitric acid and the like can be used. Moreover, as carbonate ester used for this invention, various carbonate ester can be used in the range which does not impair the effect of this invention, For example, ethylene carbonate, propylene carbonate, dimethyl carbonate, etc. can be used.

It should be noted that various materials such as an electrolytic solution (electrolyte solution), a conductive additive, and a binder may be added to the dielectric material of the present invention as long as the effects of the present invention are not impaired. For example, when the dielectric material of the present invention is used in an electrochemical element such as a capacitor, it is conceivable to add a silicone oil or an inorganic acid neutralizing agent to protect the metal electrode from acid corrosion. .

Silicone oil covers the electrode surface and prevents corrosion of the electrode by acid. Further, the neutralizing agent eliminates the inorganic acid by a neutralization reaction and prevents corrosion of the electrode by the acid.

In addition, a dispersing agent (anti-aggregation agent) such as fine particles made of an organic polymer material may be added to the dielectric material of the present invention. Examples of such organic polymer materials include polytetrafluoroethylene and polypropylene. When such a dispersant (anti-aggregation agent) is added to the dielectric material, aggregation of the reduced graphene oxide dispersed in the dielectric material can be prevented, and the surface area of the reduced graphene oxide is reduced, the short circuit and the withstand voltage are reduced. Can be suppressed.

Furthermore, the dielectric material of the present invention may be mixed with a lithium compound from the viewpoint of improving voltage performance. Examples of such lithium compounds include lithium titanate, lithium carbonate, and lithium hydroxide. Of these, lithium titanate is preferable, and is represented by the general formula: Li _x Ti _y O ₄ , where x and y are 0.8 ≦ x ≦ 1.4 and 1.6 ≦ y ≦ 2.2, respectively. More preferably, lithium titanate having a number is used. More specifically, for example, Li ₄ Ti ₅ O ₁₂ and Li ₂ Ti ₃ O ₇ are preferable.

The lithium titanate represented by the general formula: Li _x Ti _y O ₄ can be obtained, for example, by heat treating titanium oxide and a lithium compound at 760 to 1100 ° C. As the titanium oxide, either anatase type or rutile type can be used, and as the lithium compound, for example, lithium hydroxide, lithium carbonate, lithium oxide, or the like can be used.

<< Production Method of Dielectric Material of the Present Invention >>
The method for producing a dielectric material of the present invention is characterized by mixing reduced graphene oxide, an inorganic acid and / or a carbonate ester (and, if necessary, a lithium compound).

Reduced graphene oxide and inorganic acid are mixed by adding 1 to 3% of reduced graphene oxide to inorganic acid and carbonate ester, and stirring and dispersing in a glass container using a magnetic stirrer with high viscosity. This can be achieved.

The content of reduced graphene oxide in the dielectric material can be arbitrarily set as long as the effects of the present invention are not impaired. The capacitance tends to increase as the content of reduced graphene oxide increases, but as the amount of reduced graphene oxide added increases, it becomes difficult to uniformly disperse, and the raw material cost increases. End up.

Here, examples of the reduced graphene oxide that can be suitably used include “Graferrite RGO” manufactured by MICC Corporation. Further, instead of reduced graphene oxide, reduced graphene oxide is obtained by intercalating and doping at least one substance selected from silver, copper, zinc oxide, and palladium (graferrite ag007 manufactured by MICC TEC Co., Ltd.) , Graferrite cu008, Graferrite zn009, and Graferrite Pd010) can further improve the capacitance of the dielectric material.

As the inorganic acid, various inorganic acids can be used as long as the effects of the present invention are not impaired. For example, concentrated sulfuric acid, dilute sulfuric acid, nitric acid and the like can be used. In addition, when using a lithium compound, the usage-amount of an inorganic acid may be small compared with the case where a lithium compound is not used. Moreover, as carbonate ester, various carbonate ester can be used in the range which does not impair the effect of this invention, For example, ethylene carbonate, propylene carbonate, dimethyl carbonate, etc. can be used.

≪Electrochemical element≫
The electrochemical device of the present invention includes a polarizable electrode containing the dielectric material of the present invention, a separator, a first collector electrode, and a second collector electrode. Here, the dielectric material of the present invention is used as a so-called active material or a polarizable electrode itself, and in any case constitutes a polarizable electrode.

(1) Electrochemical element 1
First, the case where it manufactures based on the manufacturing technique of an electrical double layer capacitor as an example of the electrochemical element of this invention is demonstrated. The electrochemical element of the present invention is configured by sealing a polarizable electrode containing the dielectric material of the present invention, a separator, a first collector electrode, and a second collector electrode in a sealed container. As for the shape, for example, any of a cylindrical shape and a box shape may be adopted, and other shapes may be employed.

Here, FIG. 1 shows a schematic configuration diagram of an embodiment of the electrochemical device 1 of the present invention. Between a first collector electrode (positive electrode) 2 and a second collector electrode (negative electrode) 4 connected to a power source, a polarizable electrode 6 made of a dispersed liquid, gel or paste dielectric material of the present invention. And a separator 8 is provided.

Further, in the electrochemical element 1 shown in FIG. 1, since the dielectric material of the present invention is a dispersed liquid, paste or gel and has fluidity, it is used as the polarizable electrode 6 as it is, and is locally broken down. For example, it has excellent self-healing properties and is practically useful.

The “positive electrode” is an electrode that adsorbs anions when a voltage is applied to the electric double layer capacitor, and the “negative electrode” is an electrode that adsorbs cations when a voltage is applied to the electric double layer capacitor. Electrode.

The first collector electrode (positive electrode) 2 and the second collector electrode (negative electrode) 4 are not particularly limited as long as they are generally highly conductive materials, but at least a low electrical resistance metal material is preferably used. For example, copper, aluminum, gold, platinum, lead, tin, nickel, etc., and other organic insulating materials or conductive organic materials doped with iodine are used. Of these, gold, platinum, lead, tin, nickel, etc. may be used from the viewpoint of being less susceptible to acid in consideration of the case where the inorganic acid used in the production of the dielectric material of the present invention remains. .

The thickness of the first collector electrode (positive electrode) 2 and the second collector electrode (negative electrode) 4 is, for example, about 10 to 50 μm, and the first collector electrode (positive electrode) 2 and the second collector electrode (negative electrode) ) 4 is provided with a tab (not shown) for lead connection, for example.

Further, the first collector electrode (positive electrode) 2 and / or the second collector electrode (negative electrode) 4 is coated with the dielectric material of the present invention, and the coated dielectric material is dried, thereby surface treatment. It is preferable that For example, after applying the dielectric material of the present invention, the surface treatment can be achieved by drying in the atmosphere at 600 to 700 ° C. for 3 to 10 minutes.

The polarizable electrode 6 may contain a conductive additive. Examples of the conductive assistant include carbon materials other than carbon components contained in the dielectric material of the present invention such as carbon black and acetylene black, metal fine powders such as copper, nickel, stainless steel, and iron, and a mixture of metal fine powders, ITO And the like, and the like.

Moreover, the polarizable electrode 6 may contain an electrolytic solution. As the electrolytic solution, a solution obtained by dissolving an electrolyte in an organic solvent is used. As the electrolyte, for example, a quaternary ammonium salt such as tetraethylammonium tetrafluoroborate (TEA + BF4-) or triethylmonomethylammonium tetrafluoroborate (TEMA + BF4-) can be used.

Furthermore, the polarizable electrode 6 may contain a binder. The binder is not particularly limited as long as it has a binding force that can maintain the shape of the polarizable electrode 6, and various binders can be used. Examples of the binder include fluorine resins such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR) and water-soluble polymers (carboxymethylcellulose, polyvinyl alcohol, sodium polyacrylate, Dextrin, gluten, etc.) and the like.

The separator 8 prevents ohmic contact between the first collector electrode (positive electrode) 2 side and the second collector electrode (negative electrode) 4 side of the polarizable electrode 6. It has an influence. It is desirable to have flexibility, mechanical strength, and high durability.

As the material of the separator 8, various inorganic insulating materials and organic insulating materials can be used. Examples of the inorganic insulating material include a zinc oxide material, glass and ceramics, and glass wool is preferably used.

Also, examples of the organic insulating material include insulating paper used in conventional electric double layer capacitors, porous polymer films such as polyethylene and polypropylene, and non-woven fabrics. For example, there are various types of insulating paper depending on the application, but in order to achieve a high breakdown voltage, those used in equipment using a high voltage such as a transformer are preferable. Moreover, what does not swell is preferable.

When the dielectric material of the present invention is in the form of powder, granules, or agglomerates and is used as the active material of the polarizable electrode 6, the polarizable electrode 6 is not limited to the dielectric material of the present invention. In addition, a conductive additive or a binder may be included. The polarizable electrode may be divided into two and an electrolyte layer may be provided between them.

(2) Electrochemical element 2
Moreover, the electrochemical device of the present invention may have a structure as shown in FIG. FIG. 2 shows an electrochemical device 10 of the present invention that employs a typical electric double layer capacitor structure, and the electrode section includes a first collector electrode (positive electrode) 12 and a second collector electrode connected to a power source. (Negative electrode) 14, and the powder, granule, or agglomerated dielectric material of the present invention fixed and connected to the first collector electrode (positive electrode) 12 and the second collector electrode (negative electrode) 14. Including solid polarizable electrodes 16a and 16b.

The electrolyte part includes an electrolyte filled in a space between the polarizable electrodes 16a and 16b, and the space between the first collector (positive electrode) 12 side and the second collector (negative electrode) 14 side. And a separator 18 separated from each other. By applying a voltage between the first collector electrode (positive electrode) 2 and the second collector electrode (negative electrode) 4, at the interface (electric double layer) between the electrolyte and the polarizable electrodes 16a and 16b. Polarization occurs, and charges (electric capacity) are accumulated here.

Each component of the electrochemical device 10 may be the same as that of the electrochemical device 1 described with reference to FIG. 1, but the polarizable electrodes 16a and 16b may be formed in the form of powder, granule or It is a solid electrode containing an agglomerated dielectric material, and thus has, for example, a configuration including at least a binder.

The electrochemical element 10 can be a cylinder, a square, a sheet, or the like. In particular, a sheet having a thickness of 0.15 to 50 mm is lightweight and can be easily installed on a floor or a wall.

(3) Electrochemical element 3
Furthermore, the electrochemical device of the present invention may have a structure as shown in FIG. FIG. 3 is a perspective view in which a part of the electrochemical device 100 of the present invention adopting a typical lead-acid battery structure is cut out. The constituent elements of the electrochemical element 100 may be the same as those of the conventional lead acid battery except for a part, but each constituent element will be briefly described below.

In the electrochemical element 100, the battery case 102 is partitioned into a plurality of cell chambers 106 by partition walls 104, and one electrode plate group 108 is accommodated in each cell chamber 106. Although not shown, the electrode plate group 108 is configured by laminating a plurality of positive and negative electrode plates with a separator interposed therebetween. The positive electrode plate is connected to the positive electrode connecting portion 110, the negative electrode plate is connected to the negative electrode connecting portion 112, and the electrode plate group 108 is connected in series with the electrode plate group 108 in the adjacent cell chamber 106.

A lid 118 provided with a positive electrode terminal 114 and a negative electrode terminal 116 is attached to the upper opening of the battery case 102. The liquid injection port provided in the lid 118 is provided with an exhaust plug 120 having an exhaust port for discharging gas generated inside the battery to the outside of the battery.

The positive electrode plate is composed of a positive electrode lattice and a positive electrode active material layer held on the positive electrode lattice. The positive electrode active material layer is mainly composed of a positive electrode active material (PbO 2), and the positive electrode active material layer may contain, for example, a small amount of a conductive additive such as a carbon material, a binder, etc. in addition to the positive electrode active material. The positive electrode lattice is an expanded lattice that holds the positive electrode active material layer.

The positive electrode lattice is made of, for example, a Pb alloy containing at least one of Ca and Sn. As the Pb alloy, from the viewpoint of corrosion resistance and mechanical strength, a Pb—Ca alloy containing 0.01 to 0.10% by weight of Ca, a Pb—Sn alloy containing 0.05 to 3.0% by weight of Sn, Alternatively, a Pb—Ca—Sn alloy containing Ca and Sn can be used. The positive grid is preferably composed of a Pb—Ca—Sn alloy containing 0.03 to 0.10 wt% Ca and 0.6 to 1.8 wt% Sn. More preferably, the Pb—Ca—Sn alloy contains 0.8 to 1.8% by weight of Sn.

In addition, the Pb alloy containing at least one of Ca and Sn used for the positive electrode lattice and the positive electrode connection part substantially does not contain Sb. However, the lead alloy may contain 0.002% by weight or less of Sb as an impurity that does not adversely affect the battery performance due to an increase in the liquid reduction amount and the self-discharge amount. If the Sb content in the positive electrode grid and the positive electrode connecting member is about this level, Sb does not move to the negative electrode plate.

Further, in order to improve the corrosion resistance of the positive grid, the lead alloy of the positive grid may contain 0.01 to 0.08 wt% Ba or 0.001 to 0.05 wt% Ag. When a lead alloy containing Ca is used, about 0.001 to 0.05% by weight of Al may be added in order to suppress the disappearance of oxidation of Ca from the molten lead alloy. Further, it may contain about 0.0005 to 0.005% by weight of Bi as an impurity.

The positive electrode grid preferably has a lead alloy layer containing 2.0 to 7.0% by weight of Sn on at least a part of the surface in contact with the positive electrode active material layer. Generation of a passive layer at the interface between the positive electrode active material layer and the positive electrode lattice is suppressed, and durability of the positive electrode plate against overdischarge is improved.

When the positive electrode lattice contains Sn, the Sn content in the lead alloy layer is preferably larger than the Sn content in the positive electrode lattice. For example, when the positive electrode lattice contains 1.6% by weight of Sn, the lead alloy layer preferably contains at least 1.6% by weight of Sn, and the Sn content in the lead alloy layer is 3.0-6. More preferably, it is 0% by weight. If the Sn content of the lead alloy layer is smaller than that of the positive electrode lattice, the effect of Sn described above is reduced due to the presence of the lead alloy layer having a low Sn content at the interface between the positive electrode lattice and the positive electrode active material.

Next, the negative electrode plate is composed of a negative electrode lattice and a negative electrode active material layer held by the negative electrode lattice. The negative electrode active material layer is mainly composed of a negative electrode active material (Pb). In the negative electrode active material layer, in addition to the negative electrode active material, for example, a shrinkage-preventing agent such as lignin and barium sulfate, a conductive assistant such as a carbon material, or a binder May be included in a small amount. The negative electrode lattice is an expanded lattice in which the negative electrode active material layer is held.

The negative electrode lattice and the negative electrode connection portion are made of, for example, a Pb alloy substantially free of Sb and containing at least one of Ca and Sn. However, the Pb alloy may contain a trace amount of Sb of less than 0.001% by weight as an impurity. If the Sb content is such an amount, the amount of self-discharge and the amount of liquid electrolyte decrease do not increase.

As the negative electrode lattice, a Pb—Ca—Sn alloy may be used in the same manner as the positive electrode lattice, but the negative electrode lattice is not necessarily corroded as compared with the positive electrode plate, and therefore does not necessarily include Sn. In order to improve the strength of the negative electrode lattice or improve the flowability of molten lead in the production of the lattice, a Pb alloy containing 0.2 to 0.6% by weight of Sn may be used in the negative electrode lattice. From the viewpoint of mechanical strength, a Pb alloy containing 0.03 to 0.10% by weight of Ca may be used.

The negative electrode active material layer contains 0.0001 to 0.003% by weight of Sb. When the negative electrode active material layer contains Sb having a hydrogen overvoltage lower than that of the negative electrode active material, the charge potential of the negative electrode plate is increased, so that the charge acceptability of the negative electrode plate is greatly improved. Moreover, since Sb in the negative electrode active material layer hardly dissolves into the electrolytic solution, corrosion of the negative electrode lattice can be suppressed.

Particularly, when the Sb content in the negative electrode active material layer is 0.0001% by weight or more, the life characteristics are improved. On the other hand, when the Sb content in the negative electrode active material layer exceeds 0.003% by weight, the corrosion of the ears of the negative electrode lattice gradually proceeds. Since the effect of suppressing the corrosion of the negative electrode lattice and the effect of suppressing the decrease in the amount of the electrolyte accompanying the charge / discharge cycle can be remarkably obtained, the Sb content in the negative electrode active material layer is 0.0001 to 0.001 wt. % Is preferred.

For the addition of Sb to the negative electrode active material layer, for example, a compound containing Sb such as Sb, an oxide or sulfate of Sb, or an antimonate may be added to the negative electrode paste when the negative electrode paste is produced. In addition to this, Sb can be electrodeposited on the negative electrode active material by electrolytic plating by immersing the negative electrode plate in an electrolytic solution containing Sb ions, for example, dilute sulfuric acid containing antimony sulfate or antimonate. Good.

Generally, a microporous polyethylene sheet is used for the separator. Carbon may be included in polyethylene in order to improve ionic conductivity. The microporous polyethylene sheet has pores having a pore diameter of about 0.01 to 1 μm through which the electrolytic solution can permeate. When the pore diameter exceeds 1 μm, the active material easily passes through the separator.

Further, a fiber mat having acid resistance may be used for the separator. As the fiber, a synthetic fiber such as a glass fiber having a fiber diameter of 0.1 to 2 μm or a polypropylene resin fiber having a fiber diameter of 1 to 10 μm is used. The separator is preferably made of an acid-resistant fiber mat in that the positive electrode active material is prevented from falling off the positive electrode plate and excellent cycle life characteristics are obtained.

Here, each cell chamber 106 is injected with sulfuric acid, which is an electrolytic solution, so as to immerse the entire electrode plate group 108 in the same manner as a normal lead-acid battery.

As mentioned above, although the typical example of the dielectric material of this invention and the electrochemical element using the same was demonstrated, this invention is not limited only to these, In the range of the technical idea of this invention, various. This design change is possible, and all such design changes are included in the present invention. Hereinafter, although the dielectric material of this invention is demonstrated more concretely using an Example, it cannot be overemphasized that this invention is not what is limited to this Example.

Example 1
Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide in which silver is intercalated and doped) and sulfuric acid (30% aqueous solution) are mixed, and 0.5% by weight of graferrite ag007 is dispersed. A dielectric material 1 was obtained.

<< Example 2 >>
In the same manner as in Example 1, a mixture of graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide in which silver is intercalated and doped) and sulfuric acid are mixed to obtain 1.0 wt% of graferrite ag007. A dispersed dielectric material 2 was obtained.

Example 3
In the same manner as in Example 1, a mixture of graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide in which silver is intercalated and doped) and sulfuric acid were mixed to obtain 2.0 wt% of graferrite ag007. A dispersed dielectric material 3 was obtained.

Example 4
In the same manner as in Example 1, GRCC ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide in which silver is intercalated and doped) and sulfuric acid are mixed, and 3.0% by weight of graferrite ag007 is obtained. A dispersed dielectric material 4 was obtained.

[Capacitance measurement]
Using the dielectric materials 1 to 4 obtained in Examples 1 to 4, the measurement element 200 shown in FIG. 4 was produced, and the capacitance was measured. As a comparative example, the same measurement was performed using only sulfuric acid instead of the dielectric materials 1 to 4. Each measurement was carried out 4 times, and the obtained results are shown in FIG.

FIG. 5 shows that the capacitance increases as the content of graferrite ag007 in the dielectric material increases. Further, the increase in the capacitance is almost proportional to the content of graferrite ag007.

Example 5
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 1.0 wt% graferrite ag007 were dispersed. A glass wool / glass sheet used as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced, and the capacitance was measured. The thickness of the carbon sheet was 0.75 mm. The obtained capacitance is shown in Table 1.

Example 6
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 2.0 wt% graferrite ag007 were dispersed. Glass wool used as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced to measure the capacitance. The thickness of the carbon sheet was 0.75 mm. The obtained capacitance is shown in Table 1.

Example 7
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 0.5 wt% graferrite ag007 were dispersed. Glass wool used as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced to measure the capacitance. The thickness of the carbon sheet was 0.16 mm. The obtained capacitance is shown in Table 1.

Example 8
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 0.5 wt% graferrite ag007 were dispersed. A multilayer measuring element 300 shown in FIG. 6 is impregnated with a biaxially stretched polypropylene film (OPP) having a small number of medium holes (generally about 1 μm to 10 μm, hereinafter the same) made by Oji Paper Co., Ltd., used as a separator. The capacitance and internal resistance were measured. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

Example 9
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 0.5 wt% graferrite ag007 were dispersed. The dielectric material is impregnated into a biaxially stretched polypropylene film (OPP) made of Oji Paper, which has a large number of holes, used as a separator, and a laminated measuring element 300 shown in FIG. 6 is manufactured to measure capacitance and internal resistance. Went. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

Example 10
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0% by weight of graferrite RGO and 0.5% by weight of graferrite ag007 were dispersed. The dielectric material is impregnated into a biaxially stretched polypropylene film (OPP) having a large number of small holes made of Oji Paper (approximately 1 μm or less, the same applies hereinafter) used as a separator to produce a laminated measuring element 300 shown in FIG. The capacitance and internal resistance were measured. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

Example 11
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 0.5 wt% graferrite ag007 were dispersed. Solid glass wool (glass cloth net type 200 μm (Pega GC), glass fiber needle mat (heat press) 2 mm (Pega NM)) used as a separator is impregnated with the dielectric material, and is shown in FIG. A laminated measuring element 300 was produced and the capacitance and internal resistance were measured. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

Example 12
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 0.5 wt% graferrite ag007 were dispersed. A three-layered polypropylene sheet (Spred top manufactured by Maeda Kosen Co., Ltd.) used as a separator is impregnated with the dielectric material to produce a laminated measuring element 300 shown in FIG. Measurements were made. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

Example 13
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 0.5 wt% graferrite ag007 were dispersed. A solid glass wool used as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced to measure capacitance and internal resistance. Here, sulfuric acid containing reduced graphene oxide was applied to the carbon plate, and the carbon plate was held in the atmosphere at 600 ° C. for 10 minutes to perform surface treatment. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

<< Example 14 >>
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 0.5 wt% graferrite ag007 were dispersed. A solid glass wool used as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced to measure capacitance and internal resistance. Here, sulfuric acid containing reduced graphene oxide was applied to the carbon plate, and the carbon plate was kept in the atmosphere at 600 ° C. for 3 minutes to perform surface treatment. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

Example 15
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite pd010 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide doped with palladium intercalated) And sulfuric acid were mixed to obtain a dielectric material in which 3.0% by weight of graferrite RGO and 0.001% by weight of graferrite pd010 were dispersed. Solid glass wool (knitted) used as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced to measure capacitance and internal resistance. Here, sulfuric acid containing reduced graphene oxide was applied to the carbon plate, and the carbon plate was held in the atmosphere at 600 ° C. for 10 minutes to perform surface treatment. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

<< Example 16 >>
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite zn009 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide intercalated and doped with zinc oxide) ) And sulfuric acid were mixed to obtain a dielectric material in which 3.0% by weight of graferrite RGO and 0.5% by weight of graferrite pd010 were dispersed. A solid glass wool used as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced to measure capacitance and internal resistance. Here, sulfuric acid containing reduced graphene oxide was applied to the carbon plate, and the carbon plate was held in the atmosphere at 600 ° C. for 10 minutes to perform surface treatment. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

<< Example 17 >>
In the same manner as in Example 1, Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and Graferrite ag007 manufactured by MICC TEC Co., Ltd. (reduced graphene oxide obtained by intercalating and doping silver) And sulfuric acid were mixed to obtain a dielectric material in which 3.0 wt% graferrite RGO and 0.5 wt% graferrite ag007 were dispersed. Solid glass wool (knitted) used as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced to measure capacitance and internal resistance. Here, sulfuric acid containing reduced graphene oxide was applied to the carbon plate, and the carbon plate was held in the atmosphere at 600 ° C. for 10 minutes to perform surface treatment. The thickness of the carbon sheet was 0.16 mm. Table 1 shows the obtained capacitance and internal resistance.

<< Example 18 >>
In the same manner as in Example 1, grafer ferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd. and sulfuric acid were mixed to obtain a dielectric material in which 3.0% by weight of graferrite RGO was dispersed. A solid glass wool used as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced to measure capacitance and internal resistance. Here, sulfuric acid containing reduced graphene oxide was applied to the carbon plate, and the carbon plate was held in the atmosphere at 600 ° C. for 10 minutes to perform surface treatment. The thickness of the carbon sheet was 0.75 mm. Table 1 shows the obtained capacitance and internal resistance.

Example 19
Li ₄ Ti ₅ O ₁₂ , Graferrite RGO (reduced graphene oxide) manufactured by MICC TEC Co., Ltd., PTFE resin (50 wt% weight dispersion: binder), and sulfuric acid are mixed, and 40 wt% A dielectric material in which Li ₄ Ti ₅ O ₁₂ , 10% by weight of Graferrite RGO and 10% by weight of PTFE 50% dispersion was dispersed was obtained. A glass nonwoven fabric (glass fiber sheet) as a separator was impregnated with the dielectric material, and a laminated measuring element 300 shown in FIG. 6 was produced to measure capacitance and internal resistance. Here, sulfuric acid containing reduced graphene oxide was applied to the carbon plate. The thickness of the graphene sheet was 0.5 mm. Table 1 shows the obtained capacitance and internal resistance.

From the results shown in Table 1, all of the products obtained by adding graferrite ag007 to 3.0% graferrite RGO have a high capacitance. It is not so much affected by the added amount of ag007 (Examples 5 to 7).

In addition, when using an organic insulating material as a separator (Examples 8 to 10), when using glass wool (Examples 5 to 7) and solid glass wool, which are inorganic insulating materials (Examples 11 and 13 to 17). The one has a higher capacitance. Even when an organic insulating material is used as the separator, a case where three polypropylene sheets are stacked and used (Example 12) shows a high capacitance.

Further, when the surface treatment was performed on the carbon plate as the collecting electrode (Examples 13 and 14), the capacitance was higher than that when the surface treatment was not performed. In addition, when the time other than the surface treatment time is the same, when the time for drying the dielectric material applied to the carbon plate is 3 minutes (Example 14), it is 10 minutes than when the time is 10 minutes (Example 13). High capacitance is shown.

Addition of reduced graphene oxide intercalated and doped with at least one substance selected from silver, copper, zinc oxide, and palladium as compared with the case of only graferrite RGO (Example 18) If this is the case, the capacitance is higher.

It can also be seen that when a dielectric material containing a lithium compound is used, the performance (capacitance) is remarkably improved in the laminated type (Example 19).

DESCRIPTION OF SYMBOLS 1 ... Electrochemical element 2 ... 1st collector electrode (positive electrode)
4 ... Second collector (negative electrode)
6 ... Polarizable electrode 8 ... Separator 10 ... Electrochemical element (electric double capacitor structure)
12... First collector electrode (positive electrode) in electric double capacitor structure
14 ... Second collector electrode (negative electrode) in electric double capacitor structure
16a, 16b ... Polarizable electrode 18 in electric double capacitor structure ... Separator 20 in electric double capacitor structure ... Electrolytic solution 100 ... Electrochemical element (lead storage battery structure)
DESCRIPTION OF SYMBOLS 102 ... Battery case 104 ... Partition 106 ... Cell chamber 108 ... Electrode plate group 110 ... Positive electrode connection part 112 ... Negative electrode connection part 114 ... Positive electrode terminal 116 ... Negative electrode terminal 118 ... Lid 120 ... Exhaust plug 200 ... Measuring element 202 ... Carbon rod 204 ... Dielectric material 206 ... Container 208 ... Plug 300 ... Multilayer measuring element 302 ... Carbon plate 304 ... Carbon sheet 306 ... Dielectric material impregnated separator

Claims (9)

1. Reduced graphene oxide,
   Containing an inorganic acid and / or a carbonate ester,
   A dielectric material characterized by
2. Further containing a lithium compound,
   The dielectric material according to claim 1.
3. The reduced graphene oxide is intercalated and doped with at least one substance selected from silver, copper, zinc oxide, and palladium;
   The dielectric material according to claim 1, wherein:
4. A polarizable electrode comprising at least the dielectric material according to any one of claims 1 to 3;
   A separator;
   Including a first collector electrode and a second collector electrode;
   An electrochemical element characterized by the above.
5. The dielectric material according to any one of claims 1 to 3 is applied to the first collector electrode and / or the second collector electrode, and the applied dielectric material is dried, thereby allowing the first collector electrode to dry. The collector electrode and / or the second collector electrode are surface-treated,
   The electrochemical device according to claim 3.
6. Including the electrochemical element according to claim 4 or 5,
   A power storage device characterized by the above.
7. Reduced graphene oxide,
   Mixing with inorganic acid and / or carbonate ester,
   A method for producing a dielectric material characterized by the above.
8. Further containing a lithium compound,
   The method for producing a dielectric material according to claim 7.
9. The reduced graphene oxide is in powder form, and at least one substance selected from silver, copper, zinc oxide, and palladium is intercalated and doped;
   The method for producing a dielectric material according to claim 7 or 8, wherein:

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