KR101933512B1 - electrode composition in pseudo type capacitor, electrode using the same and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an electrode composition for a water capacitor, an electrode for a water capacitor including the same, and a method for manufacturing the electrode capacitor. More particularly, the present invention relates to an electrode composition for a water capacitor, The present invention relates to an electrode capacitor capable of providing an electrode for a capacitive capacitor which is greatly improved, and capable of greatly improving a non-discharge capacity, a charge / discharge efficiency, an energy density, an output density and a long-term life stability.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode composition for a water-storage capacitor, an electrode for a water-storage capacitor including the electrode composition,

The present invention relates to an electrode composition for a water capacitor, a water capacitor electrode including the same, and more particularly to an electrode composition for a water capacitor having an excellent non-discharge capacity, charge / discharge efficiency, energy density and power density, A capacitor electrode and a method of manufacturing the same.

In recent years, driving power sources for portable electronic and communication devices and electric vehicles are demanding not only high energy density but also high power energy sources. Lithium-based secondary batteries and super-capacitors using electrochemical principles are typical examples of recently developed energy storage devices in response to these demands.

In the case of the lithium-based secondary battery, the ability to provide high output energy is insufficient, and when the battery operates in a severe environment, the life of the battery deteriorates remarkably.

On the other hand, the supercapacitor utilizes a reversal faradaic oxidation / reduction reaction at the electrode / electrolyte interface, which has an energy density lower than that of the lithium-based secondary battery but has a significantly higher output density, And it is known that it exhibits a significantly superior value in charge / discharge time and life span.

The supercapacitor can be roughly divided into three types. An electric double layer capacitor (EDLC) in which electrical energy is accumulated by charge separation due to electrostatic attraction in an electric double layer near the electrode / electrolyte interface, and an electrode / electrolyte There are pseudo capacitors and hybrid capacitors in which electrical energy is accumulated by a reversible electrochemical oxidation / reduction reaction at the interface.

In particular, among the super capacitors, the water storage capacitor utilizes an electrochemical reaction in which the basic energy storage principle occurs in a metal oxide such as a battery. In other words, the battery exhibits a plateau at a constant voltage and time curve with charge and discharge, while the metal oxide electrochemical capacitors exhibit a straight line curve. The reason why the capacitors are called capacitors other than capacitors is that the characteristics of the capacitors are normal due to the formation of the electric double layer like electric double layer capacitors and it is difficult to obtain the capacitor characteristic by the electrochemical reaction, Because of the characteristics of.

Conductive polymers are made by using conjugated polymers. Conjugated polymers have higher capacity than carbon, have excellent mechanical, chemical and optical properties, and have corrosion stability, chemical or electrochemical Has the possibility of synthesis. These conjugated polymers are based on having atoms, especially between carbon atoms and carbon atoms, and between single and double bonds between carbon and nitrogen atoms. The compounds having such a conjugate bond do not exhibit conductivity in themselves, but doping with a dopant results in a conductive polymer.

The conductive polymer is used in various applications such as solar cells, light-weight batteries, light emitting diodes, energy storage devices, and sensors due to the above characteristics.

Korean Unexamined Patent Publication No. 2001-0138084 discloses an aluminum polymer capacitor and a manufacturing method thereof. Such a water-based capacitor including a conductive polymer has attracted a lot of attention due to advantages such as low cost, environmental stability, and easy synthesis. .

However, such a water-containing capacitor including a conductive polymer has a problem that not only the charging capacity is sufficient, but also the cyclic life is low and the energy density is low.

Korean Public Release No. 2008-0112759 (published on December 26, 2008) Korean Registration No. 20-0433930 (Notification Date: Dec. 13, 2006)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and one of the objects of the present invention is to provide an electrode composition for a capacitive capacitor having an excellent non-discharge capacity.

A second problem to be solved by the present invention is to provide an electrode for a tap capacitor which is excellent in charge / discharge efficiency, energy density and output density as well as non-discharge capacity.

A third object of the present invention is to provide a method of manufacturing an electrode for a water-cooled capacitor having a low equivalent serial resistance (ESR).

In order to solve the above-described problems, the present invention relates to an electrode composition for a tap capacitor, which comprises a polymer compound containing a repeating unit represented by the following formula (1), a composite metal oxide and a binder.

[Chemical Formula 1]

X and y are molar ratios of monomers constituting the repeating unit, x + y = 1, x is a rational number satisfying 0? X? 1, z is a weight average molecular weight of 10,000 to 50,000 .

As a preferred embodiment of the present invention, in the electrode composition of the present invention, the composite metal oxide includes porous MnO ₂ powder and TiO ₂ particles, and all or a part of the TiO ₂ particles are embedded in the pores of the MnO ₂ powder And may be integrated.

In one preferred embodiment of the present invention, the TiO ₂ particles have an average particle size of 1 to 10 nm and a BET specific surface area of 350 m ² / g or more.

In one preferred embodiment of the present invention, the porous MnO ₂ powder may have an average particle size of 10 to 30 nm and a BET specific surface area of 200 m ² / g or more.

In one preferred embodiment of the present invention, the composite metal oxide may include porous MnO ₂ powder and TiO ₂ particles in a weight ratio of 1: 0.02 to 0.90.

In one preferred embodiment of the present invention, 2 to 7 parts by weight of the composite metal oxide and 800 to 1,000 parts by weight of the binder may be added to 100 parts by weight of the polymer compound.

In one preferred embodiment of the present invention, the binder may include at least one of nafion, polyvinylidene fluoride (PVdF), and polytetrafluoroethylene (PTFE).

Another object of the present invention is to provide an electrode for a water-cooled capacitor produced by using the above-described various electrode compositions for a water-capacitor, wherein a polymer compound containing a repeating unit represented by the above-mentioned formula (1) and a composite metal oxide are mixed at a ratio of 1: 0.02 To 0.07 weight ratio, and the composite metal oxide includes porous MnO ₂ powder and TiO ₂ particles, and all or a part of the TiO ₂ particles may be contained in the pores of the MnO ₂ powder.

In one preferred embodiment of the present invention, the electrode for a water-cooled capacitor of the present invention may have a non-discharge capacity of 300 to 500 F / g as measured by cyclic voltammetry.

In one preferred embodiment of the present invention, the electrode for a water-cooled capacitor of the present invention may have Equivalent Serial Resistance (ESR) of 1.05 to 1.70? / Cm 2 when measured by an impedance method.

As a preferred embodiment of the present invention, the electrode for a water-cooled capacitor of the present invention may have an energy density of 4.6 to 8.0 wh / kg when measured by a constant-current discharge method.

In one preferred embodiment of the present invention, the electrode for a water-cooled capacitor of the present invention may have an output power density of 2.0 to 4.0 kW / kg as measured by the DC ESR method.

It is still another object of the present invention to provide a method for producing an electrode for a water-cooled capacitor, which comprises mixing and stirring a polymer compound containing a repeating unit represented by Chemical Formula 1, a composite metal oxide and a binder, ; And forming the electrode composition. The electrode for a tap capacitor may be manufactured by a process including:

In a preferred embodiment of the present invention, the composite metal oxide is prepared by mixing a mixture of potassium permanganate, ascorbic acid, and TiO ₂ particles with ionized water and mixing the mixture in one step; A second step of baking the agitated product at 50 to 200 DEG C for 20 to 30 hours to produce a sintered product; And filtering and washing the fired product and then drying the fired product.

In one preferred embodiment of the present invention, when the composite metal oxide is used, the mixture may contain 100 to 300 parts by weight of ascorbic acid and 15 to 45 parts by weight of TiO ₂ particles per 100 parts by weight of potassium permanganate.

In one preferred embodiment of the present invention, the composite metal oxide, the mixture of the first step and the ionized water may be contained at a weight ratio of 1: 1 to 1.4.

In one embodiment of the present invention, also in the capacitor electrode production method for the polymer compound is a compound represented by formula (2), water and perchloric acid (perchloric acid, HClO ₄₎ reaction vessel to ammonium persulfate, comprising a solvent ( Ammonium Persulfate); And 2) a step of refluxing the reaction mixture at 0 to 4 to prepare the polymer compound.

(2)

As a preferred embodiment of the present invention, the perchloric acid solvent in the step (1) of the method for producing an electrode for a water-cooled capacitor of the present invention may be an aqueous solution of perchloric acid at a concentration of 48 to 72% by weight.

As a preferred embodiment of the present invention, the polymer compound of the method for manufacturing an electrode for a water-cooled capacitor of the present invention is characterized in that the polymer compound comprises 1,800 to 10,000 parts by weight of ionized water, 300 to 2,200 parts by weight of perchloric acid solvent , And 70 to 600 parts by weight of ammonium persulfate.

In one preferred embodiment of the present invention, the polymer compound includes 2,000 to 3,100 parts by weight of ionized water, 400 to 650 parts by weight of perchloric acid solvent, and 95 to 160 parts by weight of ammonium persulfate per 100 parts by weight of the compound represented by Formula 2 can do.

The diaphragm capacitor electrode fabricated from the electrode composition for a water capacitor of the present invention can significantly improve the non-capacity, charge / discharge efficiency, energy density and power density of the diaphragm capacitor into which the electrode of the present invention is introduced.

Hereinafter, the present invention will be described in more detail.

As described above, a pseudo capacitor uses a metal oxide and a conductive polymer. Conductive polymers are prepared using conjugation polymers. Conjugated polymers have higher capacity than carbon, have excellent mechanical, chemical and optical properties, and have the potential for corrosion stability, chemical or electrochemical synthesis. These conjugated polymers are based on having atoms, especially between carbon atoms and carbon atoms, and between single and double bonds between carbon and nitrogen atoms. The compounds having such a conjugate bond do not exhibit conductivity in themselves, but doping with a dopant results in a conductive polymer.

Such water-conductive capacitors including conductive polymers are attracting much attention because of their low cost, environmental stability, and easy synthesis. However, such a water-containing capacitor including a conductive polymer has a problem that not only the charging capacity is sufficient, but also the cyclic life is low and the energy density is low.

Accordingly, the present invention provides an electrode composition for a capacitive capacitor comprising a polymer compound represented by a specific formula, a specific composite metal oxide, and a binder. The present invention has been made to solve the above problems and provides a nonvolatile capacity, charge / discharge efficiency, And an electrode for a tap capacitor having an excellent output density can be provided.

The electrode composition for a water-cooled capacitor of the present invention comprises a polymer compound containing a repeating unit represented by the general formula (1), a metal oxide and a binder.

[Chemical Formula 1]

X and y are molar ratios of monomers constituting the repeating unit, x + y = 1, x is a rational number satisfying 0? X? 1, z is a weight average molecular weight of 10,000 to 50,000 .

In Formula 1, the sum of x and y satisfies 1, and x is a rational number satisfying 0? X? 1. In other words, the polymer compound may change to the oxidation-reduction state in accordance with the change of x value. Specifically, the polymer compound is represented by an oxidation type compound represented by the following formula (1-1), an intermediate oxidation type compound represented by the following formula (1-2), and a reduced type compound represented by the following formula (1-3) .

[Formula 1-1]

X + y = 1, x is a rational number satisfying 0.5 < x? 1, z is a rational weight average molecular weight of 10,000 To 50,000.

[Formula 1-2]

In Formula 1-2, x and y are molar ratios of monomers constituting the repeating unit, x + y = 1, x = 0.5, z is a weight average molecular weight of 10,000 to 50,000 .

[Formula 1-3]

X and y are molar ratios of monomers constituting the repeating unit, x + y = 1, 0? X <0.5, and z is a weight average molecular weight of 10,000 to 50,000 .

In other words, the pernigraniline base (PNP) compound is in an oxidized state, x> y in the formula (1), and the emeraldine base (EB) The leucoemeraldine base (LEB) compound is in a reduced state, and can be represented by the formula (1) where x < y.

The z in formula (1) is a rational number satisfying a weight average molecular weight of 10,000 to 50,000, preferably 20,000 to 40,000. If z is less than 10,000, a problem of reduction in electric capacity may occur. On the other hand, And a problem of moldability may occur.

The polymer compound containing the repeating unit represented by Formula 1 may be doped with perchlorate ions (ClO ₄ ^- ) and / or sulfate ions (SO ₄ ^2- ). The surface modification and / or the acid doping can be performed through the perchlorate ion (ClO ₄ ^- ) and / or the sulfate ion (SO ₄ ^2- ). The conductivity and / or conductivity of the polymer compound containing the repeating unit represented by the formula (1) Or dispersibility.

In the present invention, the composite metal oxide includes a porous MnO ₂ powder and TiO ₂ particles, and all or a part of the TiO ₂ particles are integrated in the pores of the MnO ₂ powder to form a composite metal oxide.

The TiO ₂ particles constituting the composite metal oxide may have an average particle diameter of 1 to 10 nm, preferably 1 to 8 nm, more preferably 1 to 5 nm. Such TiO ₂ particles may have a BET specific surface area of 350 m ² / g or more, and preferably a specific surface area of 360 m ² / g to 450 m ² / g. If the average particle diameter of the TiO ₂ particles exceeds 10 nm, the size of the TiO ₂ particles may be too large to completely or partially contain the TiO ₂ particles in the pores formed in the porous MnO ₂ powder.

The porous MnO ₂ powder may have an average particle diameter of 10 to 30 nm, preferably 15 to 30 nm, and more preferably 18 to 30 nm. The porous MnO ₂ powder may have a BET specific surface area of 200 m ² / g or more, and preferably 230 m ² / g to 350 m ² / g.

The composite metal oxide porous MnO ₂ powder and the TiO ₂ particles may be contained in a weight ratio of 1: 0.02 to 0.90, preferably 1: 0.2 to 0.7, more preferably 1: 0.3 to 0.6, At this time, if the TiO ₂ particle is less than 0.02 weight ratio or more than 0.90 weight ratio, there may be a problem that the non-ionic capacity, energy density, power density, etc. of the water channel capacitor using the electrode for water capacitor are decreased.

The content of the composite metal oxide in the electrode composition for a water capacitor is preferably 2 to 7 parts by weight, preferably 2.5 to 5 parts by weight, of the composite metal oxide relative to 100 parts by weight of the polymer compound. If the amount is less than 1 part by weight, the use amount thereof may be too small, and the non-electrical capacity, energy density, power density and the like of the water tap capacitor may be reduced, and it is uneconomical to use more than 7 parts by weight.

On the other hand, the binder includes at least one of nafion, polyvinylidene fluoride (PVdF) and polytetrafluoroethylene (PTFE), preferably nafion, polyvinylidene fluoride PVdF). The amount of the binder used is preferably 800 to 1,000 parts by weight, preferably 850 to 970 parts by weight, based on 100 parts by weight of the polymer compound. When the amount of the binder is less than 800 parts by weight, There may be a problem that it does not appear. If it is used in excess of 1,000 parts by weight, there may be a problem that electric properties are deteriorated because there are many binders.

In addition, the electrode composition for water-cooled capacitors of the present invention has a pH of 1.8 to 3.0, preferably a pH of 1.9 to 2.5, and more preferably a pH of 1.9 to 2.3, to increase the rate of oxidation- The polymer compound represented by the formula (1) is an oxidation-type compound represented by the following formula (1-1): an intermediate oxidation compound (formula (1-2)): The molar ratio of the reducing compound (Formula 1-3) = 0.3-0.6: 1: 0.05-0.2. When having such a molar ratio, the polymer compound represented by Formula 1 may have excellent compatibility between the metal oxide and the binder. In other words, the oxidation-reduction mechanism may be more advantageous as the number of intermediate oxidation compounds increases.

As described above, an acidic electrolyte solution may be used to enhance the oxidation-reduction characteristics through pH control of the electrode composition for the water channel capacitor. In this case, an acidic solution generally used in the art can be used as the acidic electrolyte solution. Preferably, at least one of 1 M aqueous hydrochloric acid solution, 1 M perchloric acid aqueous solution and 1 M aqueous sulfuric acid solution can be used.

The electrode for a water-cooled capacitor of the present invention prepared using the above-mentioned composition contains the polymer compound containing the repeating unit represented by the formula (1) and the composite metal oxide at a weight ratio of 1: 0.02 to 0.07, preferably 1: 0.025 to 0.05 . As described above, all or a part of the TiO ₂ particles are integrated into the pores of the porous MnO ₂ powder to form the composite metal oxide.

If the electrode for a watercapped capacitor of the present invention contains a composite metal oxide in an amount of less than 0.02 by weight and / or more than 0.07 by weight based on the weight ratio of the polymer compound, the noncontact capacity of the electrode for the watercup capacitor, equivalent serial resistance resistance and ESR, charging / discharging efficiency, energy density and power density tend to be rather low.

The electrode for a water capacitor of the present invention may have a non-discharge capacity of 300 to 500 F / g, preferably 310 to 450 F / g, as measured by cyclic voltammetry.

The electrode of the present invention may have an equivalent series resistance (ESR) of 1.05 to 1.70? / Cm 2, preferably an equivalent series resistance of 1.10 to 1.55? / Cm 2 when measured by an impedance method. And can have a charge-discharge efficiency of 85 to 98%, preferably a charge-discharge efficiency of 90 to 96% when measured by a constant-current discharge method.

Also, the electrode for a water-cooled capacitor of the present invention has an energy density of 4.6 to 8.0 wh / kg, preferably 5.2 to 7.5 wh / kg when measured by a constant-current discharge method Lt; / RTI &gt;

In addition, the electrode for a water-cooled capacitor of the present invention may have an output power density of 2.0 to 4.0 kW / kg, preferably 2.2 to 3.6 kW / kg when measured by the DC ESR method.

The electrode for a water-cooled capacitor of the present invention is produced by mixing and stirring a polymer compound containing a repeating unit represented by the formula (1), a composite metal oxide, and a binder to prepare an electrode composition; And molding the electrode composition.

The polymer compound may be prepared by the following method.

First, Ammonium Persulfate may be added to a reaction tank containing a compound represented by the following general formula (2), ionized water and perchloric acid (HClO ₄ ) as a first step.

(2)

In other words, the purified compound of formula (2) and ionized water may be added to the reaction vessel, stirring the mixture for 20 to 40 minutes, and then introducing the perchloric acid solvent into the reaction vessel. Thereafter, ammonium persulfate can be added in small amounts so that an exothermic reaction does not occur for 30 to 90 minutes.

The perchloric acid solvent means perchloric acid and may be composed of perchloric acid having a concentration of 100% or mixed with other solvent. In this case, water, ethyl acetate, chloroform, hexane and the like can be preferably used as other solvent. When water is used as a solvent for the perchloric acid solvent, the concentration is 48 to 72% by weight, preferably 54 to 66% It is very advantageous to use an aqueous solution of perchloric acid to maximize the yield. In other words, if the perchloric acid solvent is used in an amount exceeding 48% by weight or less than 72% by weight, the yield of the polymer compound may be reduced.

Next, as the second step, the polymer may be prepared by refluxing the reaction vessel at 0 to 4, preferably 0 to 2. In other words, the reaction tank is refluxed at a low temperature of 0 to 4, preferably 0 to 2, for 12 to 36 hours, preferably 18 to 30 hours. If the temperature is less than 0, There is a problem that the yield and dispersibility may be very low due to the lowering of the molecular weight. When the molecular weight exceeds 4, there is a limit to the growth of the chain type of the polymer, and when the chain type is short, I will not have it.

Next, the polymer compound may include 1,800 to 10,000 parts by weight of ionized water, 300 to 2,200 parts by weight of perchloric acid solvent, and 70 to 600 parts by weight of ammonium persulfate, based on 100 parts by weight of the compound represented by Formula 2, May include 2,000 to 3,100 parts by weight of ionized water, 400 to 650 parts by weight of perchloric acid solvent, and 95 to 160 parts by weight of ammonium persulfate per 100 parts by weight of the compound represented by the general formula (2). If the polymer compound is contained in an amount of less than 1,800 parts by weight of ionic water based on 100 parts by weight of the compound represented by the formula 2, it is difficult to control the reaction due to generation of heat due to a rapid reaction, There is a possibility that the reaction does not occur.

If the polymer compound is contained in an amount of less than 300 parts by weight perchloric acid solvent per 100 parts by weight of the compound represented by the general formula (2), reaction control is difficult due to generation of heat due to a rapid reaction, If the amount is exceeded, reaction control may occur due to generation of heat due to a rapid reaction. In addition, when the polymer compound is contained in an amount of less than 70 parts by weight of ammonium persulfate per 100 parts by weight of the compound represented by the general formula (2), the reaction may not occur. If the polymer compound is contained in an amount exceeding 600 parts by weight, The occurrence of reaction control problems can occur.

As a result, since the polymer compound of the present invention is manufactured to contain the materials in the same weight parts as described above, the electrode for a water-cooled capacitor produced by the polymer compound of the present invention has low equivalent series resistance, , The energy density and the output density can be excellent.

Next, the polymer compound prepared in Step 2 may be filtered using a vacuum filter, and then the following three steps may be performed.

Step 3 may stir the polymer compound into a mixed solution containing perchloric acid and sulfuric acid. In other words, the polymer compound is added to a mixed solution containing sulfuric acid and perchloric acid at a weight ratio of 1: 1 to 5, preferably 1: 2 to 3, at 5 to 15 캜, preferably 8 to 12 캜, Lt; / RTI &gt; for 1 hour, preferably 18 to 30 hours. Thus, perchlorate ion (ClO ₄ ^- ) and sulfate ion (SO ₄ ^2- ) can be doped into the polymer compound, and the low molecular weight compound can be selectively removed to obtain the repeating unit represented by the formula (1) The high-molecular weight compound having high electrical properties and dispersion type can be obtained.

If the mixed solution contains perchloric acid in an amount of less than 1 part by weight and / or more than 5 parts by weight based on 1 part by weight of sulfuric acid, structural instability may cause deterioration of electrical properties such as lowered electric capacity.

Finally, the polymer compound may be finally dried in a hot air oven at 40 ° C to 60 ° C.

The composite metal compound may be prepared by the following method.

Wherein the composite metal oxide is prepared by mixing a mixture of potassium permanganate, ascorbic acid, and TiO ₂ particles with ionized water and stirring the mixture; A second step of firing an agitated material to produce a fired product; Filtering and washing the fired product, and then drying the fired product.

In the process for producing a composite metal compound, the mixture in the first step may be mixed with 100 to 300 parts by weight of ascorbic acid and 15 to 45 parts by weight of TiO ₂ particles per 100 parts by weight of potassium permanganate, 130 to 250 parts by weight of ascorbic acid and 20 to 40 parts by weight of TiO ₂ particles per 100 parts by weight of potassium.

If the amount of ascorbic acid is less than 100 parts by weight, the electrical characteristics of the electrode may be deteriorated. If the amount of ascorbic acid exceeds 300 parts by weight, ascorbic acid may remain excessively and porous MnO ₂ may not be produced or the yield may be very low Can be. If the content of the TiO ₂ particles is less than 15 parts by weight or exceeds 45 parts by weight, as described above, the porous MnO ₂ And TiO ₂ particles, which may result in a decrease in the non-electrical capacity, energy density, power density, and the like of the water storage capacitor using the electrode for the water storage capacitor.

The amount of the ionized water used is preferably 1: 1 to 1.4, preferably 1: 1 to 1.25, by weight of the mixture and the ionized water. When the amount of the ionized water is less than 1 part by weight, sufficient pores are formed in MnO ₂ If it exceeds 1.4 weight ratio, it may be preferable to use within the above range, because pores are generated too much or the pore size becomes too large, so that it is difficult for the TiO ₂ particles having a small pore size in MnO ₂ to be contained.

Calcination of the step 2 performs while under 50 ~ 200 ℃ 20 to 30 hours while, preferably 20 to 30 hours in a 20 ~ for 30 hours, and more preferably 120 ~ 180 ℃ under 90 ~ 180 ℃, CO ₂ And synthesized MnO ₂ A pore is generated in the surface. In this case, the firing temperature can be a problem that can not be MnO ₂ is generated is less than 50 ℃, with a potassium permanganate rapid reaction when it is more than 200 ℃ becomes a large amount of CO ₂ generated, which causes a rather MnO ₂ There is a problem that the non-discharge capacity is greatly reduced. If the calcination time is less than 20 hours, the porous MnO ₂ The yield may be lowered, and if it exceeds 30 hours, the yield may not be improved, which is uneconomical. The fired product is a porous MnO ₂ powder containing TiO ₂ particles, wherein all or a part of the TiO ₂ particles are integrated in the pores of the MnO ₂ powder.

Next, the step of filtering and washing the fired product and then drying the fired product may be carried out to obtain a final composite metal oxide. At this time, the filtering and washing can be performed through a general method used in the art, and the impurities such as TiO ₂ particles which are inherent in the pores of the MnO ₂ powder and unified through filtering and washing are removed. Drying can also be performed using a conventional method used in the art. In one preferred embodiment, the washed sinter may be put into a vacuum oven and dried at 50 ° C to 80 ° C.

By performing the manufacturing process as described above, a composite metal oxide having the above-described size, characteristics and the like can be produced.

On the other hand, in the step of producing an electrode composition in the method for producing an electrode for a water-storage capacitor of the present invention, an acidic electrolytic solution is introduced into a reaction tank before forming the electrode composition to adjust the pH of the electrode composition for water- 1.9 to 2.5, more preferably to a pH of 1.9 to 2.3. The polymer compound represented by Formula 1 is an oxidizing compound (Formula 1-1): an intermediate oxidizing compound (Formula 1-2): a reducing compound (Formula 1) -3) = 0.3 to 0.6: 1: 0.05 to 0.2. When having such a molar ratio, the polymer compound represented by Formula 1 may have excellent compatibility between the metal oxide and the binder.

The method of forming the electrode composition can be carried out by adjusting the size, shape, etc. according to the purpose of use through a general method used in the art.

The electrode for a tap capacitor manufactured by this method can have excellent mechanical and electrical properties as described above.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

[ Example ]

Preparation Example  1: Preparation of Polymer Compound

500 g of ionized water and 19.4 g of a purified compound represented by the following formula (2) were placed in a reaction vessel, stirred for 30 minutes, and then 100.45 g of a 60% by weight aqueous solution of perchloric acid was added. Thereafter, 24 g of ammonium persulfate was slowly added to the reaction vessel for 1 hour, and the reaction was carried out by refluxing at 0 to 2 for 24 hours. After the synthesis was completed, the mixture was filtered using a vacuum filter, and stirred for 24 hours while maintaining 5 to 15 in a mixed solution containing perchloric acid: sulfuric acid = 3: 1 by weight. Finally, the polymer compound was prepared by drying in a 50 hot air oven.

(2)

Preparation Example  2 -1: Preparation of composite metal oxide

160 parts by weight of ascorbic acid, 635 parts by weight of TiO ₂ particles having a BET specific surface area of 375 to 380 m ² / g and an average particle diameter of 2 to 5 nm were mixed and stirred to prepare 100 parts by weight of potassium permanganate, The above mixture and ionized water were mixed at a weight ratio of 1: 1.15 and then stirred to prepare a stirring product.

Next, the agitated product was fired at 70 DEG C for 24 hours to obtain a fired product.

Next, after filtering was performed, 100 parts by weight of the filtered sinter was put into 400 parts by weight of water and washed with water.

Next, the washed fired product was put in a vacuum oven and dried at 67 to 68 ° C for 24 hours to prepare a composite metal oxide as shown in Table 1 below.

Preparation Example  2 -2 ~ Preparation Example  2 -5: Preparation of composite metal oxide

Composite metal oxides having the composition ratios shown in Table 1 below were prepared by controlling the content of potassium permanganate, ascorbic acid, and TiO ₂ particles as a mixture component in the same manner as in Preparation Example 1-1.

Example of comparison preparation  1: Manufacture of metal oxides

A metal oxide was prepared in the same manner as in Preparation Example 1-1, except that the TiO ₂ particles were not used and the mixture was calcined to obtain a BET specific surface area of 206 m ² / g and an average particle size of 24 to 25 nm Mesoporous MnO ₂ powder was prepared.

division Composite metal oxide
(MnO ₂ + TiO ₂ ) TiO _{2 in} composite metal oxide particle Composite metal oxide
MnO ₂ And TiO ₂
Weight ratio BET
Specific surface area
(m ² / g) Average particle diameter
(nm) BET
Specific surface area
(m ² / g) Average particle diameter
(nm) Preparation Example 2-1 210 24-25 375 to 380 2 to 5 1: 0.07 Preparation Example 2-2 219 25 ~ 26 375 to 380 2 to 5 1: 0.2 Preparation Example 2-3 228 25 ~ 26 375 to 380 2 to 5 1: 0.43 Preparation Example 2-4 215 26-27 375 to 380 2 to 5 1: 0.67 Preparation Example 2-5 220 25 ~ 26 375 to 380 2 to 5 1: 0.88 Comparative Preparation Example 1 206 26-27 - - -

Example  One

9.8 g of the polymer compound prepared in Preparation Example 1, 0.3 g of the composite metal oxide prepared in Preparation Example 2-1 and 90 g of nafion were mixed and stirred to prepare a mixed solution. Thereafter, an acidic electrolytic solution (type: 1M hydrochloric acid aqueous solution) was added to the mixed solution to adjust the pH to about 2.2 to 2.3 to prepare an electrode composition. At this time, the polymer compound contained the oxidizing compound (Formula 1-1): the intermediate oxidizing compound (Formula 1-2): the reducing compound (1-3) = 0.45: 1: 0.12.

Next, the electrode composition was coated on Carbon-Glass to a thickness of 6 μm using a spin coater to prepare an electrode for a water condenser.

Example  2 to 5 and Comparative Example  One

Examples 2 to 5 and Comparative Example 1 were produced in the blend ratios shown in Table 2 below, and the remaining conditions except for blending ratios were prepared in the same manner as in Example 1.

Comparative Example  2 ~ Comparative Example  4

Comparative Example 2 was carried out in the same manner as in Example 1 except that porous MnO ₂ powder (BET specific surface area 210 m ² / g, average particle diameter 26 to 27 nm) and TiO ₂ particles (specific surface area 375 to 380 m ² / g and an average particle diameter of 2 to 5 nm) were prepared as shown in Table 3 below, and then coated to a thickness of 6 μm in the same manner as in Example 1 to prepare an electrode for a water-storage capacitor.

Also, in Comparative Examples 3 to 4, electrode compositions were prepared so as to have the compositions shown in Table 3, as in Comparative Example 2, and then coated to a thickness of 6 μm using each of the electrodes to prepare an electrode for a tap capacitor.

division Polymer compound
(Preparation Example 1) Composite metal
oxide Nafion The electrode composition
pH Example 1 9.7 g Preparation Example 2-1
0.3 g 90g 2.2 to 2.3 Example 2 9.7 g Preparation Example 2-2
0.3 g 90g 2.0 to 2.1 Example 3 9.7 g Preparation Example 2-3
0.3 g 90g 2.1 to 2.2 Example 4 9.7 g Preparation Example 2-4
0.3 g 90g 2.0 to 2.1 Example 5 9.7 g Preparation Example 2-5
0.3 g 90g 2.0 to 2.1 Comparative Example 1 9.7 g Comparative Preparation Example 1
0.3 g 90g 2.0 to 2.1

division Polymer compound
(Preparation Example 1) metal
oxide Nafion The electrode composition
pH Porous
Mn ₂ powder TiO ₂ particles Comparative Example 2 9.7 g 0.2 g 0.1 g 90g 2.1 to 2.2 Comparative Example 3 9.8 g 0.1 g 0.1 g 90g 2.0 to 2.1 Comparative Example 4 9.6 g 0.3 g 0.1 g 90g 2.0 to 2.1

Experimental Example  One

A three-electrode type water-based capacitor was manufactured using the electrodes for water-tap capacitor and the water-based electrolyte prepared in Examples 1 to 5 and Comparative Examples 1 to 4, and then Cyclin Boltmetry (Won-A tech, WPG100) The physical properties were measured by the following methods and are shown in Table 4 below.

(One) Non-volatile capacity  How to measure

Was measured under the conditions of a voltage of -0.2 to 1.2 V, a current of 20 mA, and a voltage of 100 mV / sec based on a cyclic voltammetry.

(2) Equivalent series resistance  How to measure

Was measured under the conditions of 10 mHz to 1 MHz, 1 V, and 20 mA based on the impedance method.

(3) Life cycle (cycle) Measurement method

(CC: 10 mA, 1 V / CV / 1 V, 30 min) and a discharge condition (1 V to 0.4 V, 1 mA discharge) based on a constant-current discharge method.

(4) Method of measuring energy density

Under the conditions of charging (CC: 10 mA, 1 V / CV / 1 V, 30 min) and discharge conditions (1 V to 0.4 V, 1 mA discharge) based on a constant-current discharge method, Respectively.

[Equation 1]

(5) Method of measuring power density

Based on the DC ESR measurement method, the half static charge? V was measured at 100 mA and 1 V and was derived using the following equation (2).

&Quot; (2) &quot;

(6) Charge / discharge efficiency  How to measure

(CC: 10 mA, 1 V / CV / 1 V, 30 min) and a discharge condition (1 V to 0.4 V, 1 mA discharge) based on a constant-current discharge method.

division Non-volatile capacity
(F / g) Equivalent series resistance
(ESR, Ω / ㎠) Energy density
(wh / kg) Power density
(kW / kg) life span
(Cycle) Charge / discharge efficiency
(%) Example 1 344 1.49 5.5 2.3 10,180 90 Example 2 377 1.22 6.5 3.0 31,250 93 Example 3 420 1.15 7.2 3.3 35,695 96 Example 4 388 1.11 7.6 3.1 33,250 92 Example 5 315 1.39 4.8 2.0 9,112 86 Comparative Example 1 350 1.57 5.2 2.2 9,280 88 Comparative Example 2 358 1.47 5.8 2.4 10,580 89 Comparative Example 3 312 1.95 5.4 2.2 9,873 88 Comparative Example 4 280 2.53 5.2 2.1 7,326 86

As can be seen from Table 4, the electrodes of Examples 1 to 5 prepared from the electrode composition using the composite metal oxide had excellent non-discharge capacity, charge / discharge efficiency, energy density, output density And long-term stability.

In particular, MnO _{2 in the} composite metal oxide And the weight ratio of TiO ₂ 1: 0.07 in Example 1 with a weight ratio of 1: 0.88, the embodiment MnO ₂ than Example 5 And TiO _{2 in} the weight ratios of 1: 0.2 to 0.7 satisfy the low equivalent series resistance, the non-discharge capacity, the charge / discharge efficiency, the energy density, the output density and the long-term life stability are greatly improved Results.

By providing the water-based capacitor electrode having excellent electrical properties using the electrode composition for a water-cooled capacitor of the present invention, the non-discharge capacity, charge / discharge efficiency, energy density, output density and long- It is possible to fabricate an improved tap capacitor.

Claims (13)

2 to 7 parts by weight of a composite metal oxide and 800 to 1,000 parts by weight of a binder, based on 100 parts by weight of a polymeric compound containing a repeating unit represented by the following formula (1)
Wherein the composite metal oxide comprises a porous MnO ₂ powder and TiO ₂ particles, wherein all or a part of the TiO ₂ particles are integrated in the pores of the MnO ₂ powder and integrated therein.
[Chemical Formula 1]

X and y are molar ratios of monomers constituting the repeating unit, x + y = 1, x is a rational number satisfying 0? X? 1, z is a weight average molecular weight of 10,000 to 50,000 .
The electrode composition for a capacitive capacitor according to claim 1, wherein the TiO ₂ particles have an average particle size of 1 to 10 nm and a BET specific surface area of 350 m ² / g or more.
The electrode composition for a capacitive capacitor according to claim 1, wherein the porous MnO ₂ powder has an average particle size of 10 to 30 nm and a BET specific surface area of 200 m ² / g or more.
The electrode composition for a capacitive capacitor according to claim 1, wherein the composite metal oxide comprises porous MnO ₂ powder and TiO ₂ particles in a weight ratio of 1: 0.02 to 0.90.
delete The method according to claim 1,
Wherein the binder comprises at least one of nafion, polyvinylidene fluoride (PVdF), and polytetrafluoroethylene (PTFE).
The electrode for a water capacitor comprises a polymer compound containing a repeating unit represented by the following formula (1) and a composite metal oxide in a weight ratio of 1: 0.02 to 0.07,
Wherein the composite metal oxide comprises porous MnO ₂ powder and TiO ₂ particles, wherein all or a part of the TiO ₂ particles are integrated in the pores of the MnO ₂ powder,
Wherein the electrode for the at least one water capacitor has an atmospheric capacity of 300 to 500 F / g as measured by a cyclic voltammetry method.
[Chemical Formula 1]

X and y are molar ratios of monomers constituting the repeating unit, x + y = 1, x is a rational number satisfying 0? X? 1, z is a weight average molecular weight of 10,000 to 50,000 .
8. The power semiconductor device according to claim 7, wherein the electrode for the water-
Has an Equivalent Serial Resistance (ESR) of 1.05 to 1.70? / Cm 2 when measured by an impedance method,
Wherein the electrode has an energy density of 4.6 to 8.0 wh / kg when measured by a constant-current discharge method.
8. The electrode for a capacitive capacitor according to claim 7, wherein the electrode for the water capacitor has an output power density of 2.0 to 4.0 kW / kg as measured by the DC ESR method.
Preparing an electrode composition by mixing and stirring a polymer compound containing a repeating unit represented by the following formula (1), a composite metal oxide and a binder; And
And molding the electrode composition,
Wherein the composite metal oxide is prepared by mixing a mixture of potassium permanganate, ascorbic acid, and TiO ₂ particles with ionized water and stirring the mixture;
A second step of baking the agitated product at 50 to 200 DEG C for 20 to 30 hours to produce a sintered product;
Filtering and rinsing the fired product, and then drying the fired product; and drying the fired product.
[Chemical Formula 1]

X and y are molar ratios of monomers constituting the repeating unit, x + y = 1, x is a rational number satisfying 0? X? 1, z is a weight average molecular weight of 10,000 to 50,000 .
The method of claim 10 wherein the mixture, relative to 100 parts by weight of acid potassium permanganate, ascorbic acid 100 to 300 parts by weight of TiO ₂ particles 15 to 45 parts by weight may capacitor electrode production method for comprising parts.
11. The method according to claim 10, wherein the mixture of the first step and the ionized water are contained at a weight ratio of 1: 1 to 1.4.
[11] The method of claim 10, wherein the polymer compound is a compound of the following formula (I): 1) introducing ammonium persulfate into a reaction tank containing a compound represented by the following formula (2), ionized water and perchloric acid (HClO ₄ ) And 2) a step of refluxing the reaction mixture at 0 to 4 to prepare the polymer compound. The method for manufacturing an electrode for a water capacitor according to claim 1,
(2)