WO2019059719A2

WO2019059719A2 - Negative electrode material for pseudocapacitor and method for manufacturing same

Info

Publication number: WO2019059719A2
Application number: PCT/KR2018/011263
Authority: WO
Inventors: 서동훈; 윤석현; 류병국
Original assignee: 주식회사 엘지화학
Priority date: 2017-09-25
Filing date: 2018-09-21
Publication date: 2019-03-28
Also published as: WO2019059719A3

Abstract

The present invention provides a negative electrode material for a pseudocapacitor which has excellent specific capacitance characteristics, and a method for manufacturing the same.

Description

Title of the Invention

Cathode material for water capacitor and manufacturing method thereof

TECHNICAL FIELD

Cross-reference with related application (s)

The present application is related to Korean Patent Application No. 10-2017-0123725 filed on September 25,

Claims the benefit of priority based on Korean Patent Application No. 10-2018-0113044, filed on Sep. 20, 2018, the entire contents of which are incorporated herein by reference.

The present invention relates to a negative electrode material for a tap capacitor excellent in non-discharge capacity characteristics and a method for manufacturing the same.

BACKGROUND ART [0002]

Electrochemical capacitors are devices that store electrical energy by forming an electrical double layer between the surface of the electrode and the electrolyte. Since the capacitor is made of electricity by an electric double layer unlike a battery in which electricity is generated by a chemical action, there is no damage to the electrode itself and the lifetime is almost infinite. Moreover, since the layer discharge time is not long, Can be stored. Accordingly, the capacitor is an electric storage material which can be particularly useful in fields requiring high output.

Recently, as the demand for an energy storage device having a high energy density and a high power output has increased, research on a supercapacitor as an energy storage device having an energy density higher than that of a conventional capacitor and an output characteristic superior to that of a lithium ion battery has been actively carried out have. These supercapacitors can be classified into electric double layer capacitors (EDLC) and water capacitors (pseudo capacitors) according to the mechanism of the energy storing mechanism.

EDLC is based on the electrochemical phenomenon of the surface of carbon materials and shows high output characteristics but is applied only in a limited field due to the relatively low energy density.

Overcoming the low capacities of these carbon-based EDLCs, it is possible to store charge through faradai c reactants on the surface of nanostructures Studies have been actively made on water capacitors which can exhibit larger capacitance by using reversible oxidation / reduction reaction at the electrode / electrolyte interface.

However, in the case of a water capacitor operated in a water-based electrolyte, the electrode material for a cathode is limited, and research on this is very important. Although vanadium oxide is known as a typical negative electrode material, it has not been able to satisfy the demand for improvement of low output characteristics due to low capacitance and low electric conductivity.

In addition, various manufacturing methods such as hydrothermal synthesis and precipitation reaction have been studied and proposed to improve capacitance and output characteristics through control of physical properties of vanadium oxide, but the electrochemical performance has not been greatly improved.

DETAILED DESCRIPTION OF THE INVENTION

[Technical Problem]

Accordingly, it is an object of the present invention to provide a negative electrode material for a water capacitor having an excellent non-discharge capacity characteristic and a manufacturing method thereof.

[Technical Solution]

According to one embodiment of the present invention, metal oxide; And a conductive inorganic material bonded to the metal oxide, wherein the composite is doped with at least one doping element selected from the group consisting of a transition metal and an amphoteric metal element, and the metal oxide- , And a cathode material for a water capacitor.

According to another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: mixing a metal oxide, a conductive inorganic material, and a raw material of a doping element; And heat treating the resultant anode material. The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

According to another embodiment of the present invention, there is provided a negative electrode and a diaphragm capacitor for a diaphragm capacitor including the negative electrode material.

【Effects of the Invention】 The negative electrode material for a tap capacitor according to the present invention is characterized in that a composite of a metal oxide and a conductive inorganic material has a laminate structure of a plate shape so that the electrolyte can easily approach the electrode surface and is doped by the doping element, The charge mobility between materials is increased, which can dramatically improve the capacitance and output characteristics when applied to the negative electrode of the tap capacitor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a graph showing X-ray powder diffraction (XRD) results of a vanadium oxide used in Example 1. FIG. 1B is a scanning electron micrograph (SEM) And lc is an enlarged view of the circle display portion in Fig.

FIG. 2A is a graph showing the XRD analysis results of the vanadium oxide used in Example 2, FIG. 2B is an SEM photograph, and FIG. 2C is an enlarged view of the circle display portion in FIG. 2B.

FIGS. 3A to 3C are SEM photographs of the composite of the vanadium oxide-carbonaceous material prepared in Example 1 with various blessings. FIG.

4A to 4C are SEM photographs of the composite of the vanadium oxide-carbonaceous material prepared in Example 2 at various magnifications.

5 is an SEM photograph of the composite of the vanadium oxide-carbonaceous material prepared in Example 3. Fig.

6 is an SEM photograph of a composite of the vanadium oxide-carbonaceous material prepared in Comparative Example 1. FIG.

7 (a) is an electron microscopic photograph of the cathode material prepared in Example 1, and b) is an elemental analysis result using an energy divergence spectrometer (EDS).

8 (a) is an electron microscopic photograph of the negative electrode material prepared in Example 2, and b) is an EDS elemental analysis result.

FIG. 9 is a CV graph measured by a cyclic voltammetry (CV) method for the negative electrode material prepared in Example 1. FIG.

FIG. 10 is a graph showing the results of measurement of a negative electrode material prepared in Example 2 by a cyclic voltammetry This is the cv graph measured.

11 is a CV graph measured by a cyclic voltammetry method for the negative electrode material prepared in Example 4. Fig.

12 is a CV graph measured by a cyclic voltammetry method for the negative electrode material prepared in Comparative Example 2. Fig.

13 is a CV graph measured by a cyclic voltammetry method for the negative electrode material prepared in Comparative Example 3. Fig.

14 is a graph showing output characteristics of negative electrode materials of Examples 1 to 3 and Comparative Example 1;

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, the terms first, second, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from another.

Also,. The terminology used herein is for the purpose of describing exemplary embodiments only. And is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms " comprise, " " comprise, " or " have ", or the like, specify that there are performed features, numbers, steps, , Step (s), component (s), or a combination thereof.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Hereinafter, the present invention will be described in more detail. The negative electrode material for a water storage capacitor according to an embodiment of the present invention, Metal oxides; And a complex of a metal oxide-conductive inorganic material including a conductive inorganic material combined with the metal oxide,

The complex is doped with at least one doping element selected from the group consisting of a transition metal and an amphoteric metal element. Specifically, in the present invention, a composite of a metal oxide-conductive inorganic material having a plate-like laminate structure is formed by using a carboxylic acid-based complexing agent in the production of a negative electrode material for a metal oxide-based capacitive capacitor, By doping with the doping element, the charge mobility between the doping element and the conductive inorganic material is increased, and the electrolyte is easily accessible to the surface of the electrode, so that the electrostatic capacity and the output characteristic can be remarkably improved. More specifically, when the metal oxide and the conductive inorganic material are combined, a semi-maleic functional group present on the surface of the conductive inorganic material by the introduction of a carboxylic acid-based complexing agent, for example, a carbon- The functional groups and the metal oxides are counteracted to form bonds. At this time, when the metal oxide has a plate-like structure like vanadium oxide, a carbon-based material is interposed between a plurality of plate-shaped vanadium oxides and laminated to form a plate-like laminated structure. As a result, the accessibility of the electrolyte to the electrode surface is improved, and the capacitance and the output characteristics of the water capacitor including the electrode can be further improved. According to an embodiment of the present invention, the effect of the metal oxide and the conductive inorganic material in the composite can be further improved by optimizing the content of the metal oxide and the conductive inorganic material. Specifically, in the composite, the metal oxide may be included in an amount of 1 to 30 parts by weight based on 100 parts by weight of the conductive inorganic material. When the content of the metal oxide is within the above range, the electrostatic capacity and the output characteristic are improved without worrying about the complexity of the complex and the uneven dispersibility or the decrease in the effect of the carbon based material on the reduction of the conductive path. Lt; / RTI > More specifically, the metal oxide may be included in an amount of 10 to 15 parts by weight based on 100 parts by weight of the conductive inorganic material. The conductive inorganic material in the composite may be carbon nanofiber (CNT), carbon nanofiber (CNF), carbon nanorods (CNRs), vapor grown carbon fiber (VGCF), graphene, Or activated carbon, and the carbon-based material may be fibrous carbon material such as CNT, CNF, CNRs, or VGCF. These materials may be used singly or in combination of two or more.

In the present invention, the term "fibrous" refers to the ratio of the major axis (length) passing through the center of the carbonaceous material to the minor axis (diameter) perpendicular to the major axis and passing through the center of the carbonaceous material, ie, aspect ratio ) Is greater than 1, has a long shape in the long axis direction, and encompasses rods, tubes, fibers, or similar forms thereof. In addition, the conductive inorganic material may be Mxene, which is known as an electromagnetic wave shielding material. Similar to graphene, the maxin has a layered structure composed of a layer of a prior metal (M) and an X layer containing at least one of carbon and nitrogen, and exhibits excellent conductivity. The front transition metal M may be Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, or the like, and may include any one or two or more of them. Specifically, in the Maxine _{_{Ti 2 C, (Ti 0.}} 5, Nbo. 5) 2 C, V 2 C, Nb 2 C, Mo 2 C, Ti 3 C 2) Zr 3 C 2) Hf 3 C 2) A carbide-based material such as Nb ₄ C ₃ , Ta ₄ C ₃ , Mo ₂ TiC ₂ , Cr ₂ TiC ₂ , or Mo ₂ Ti ₂ C ₃ ; A nitride based material such as Cr ₂ N or Ti ₄ N ₃ ; Carbonitride-based materials such as Ti ₃ CN, and the like, and any one or two or more of them may be used. Of these, any one or two or more of Ti ₃ C ₂ , Nb ₂ C and V ₂ C which are porous and can provide a wider specific surface area can be used. Considering the remarkable effect of the control of the conductive inorganic material, the conductive inorganic material may be more specifically CNT. In the case of CNT, it has a hollow at the center, and it has a better effect of improving capacitance due to the effect of ball tunneling (electron tunneling) and the strength of particle shape maintenance during charging / discharging have. More specifically, when the diameter is lnm 200nm, or 5nm to 50nm, or 5 to 20nm.

In the present invention, the diameter of the CNT can be measured by a conventional method such as a scanning electron microscope observation.

In addition, the carbon nanotube may be a single wall, a double wall, or a multi-wall carbon nano-flow, and the multi-wall CNT may exhibit excellent electrical and mechanical characteristics due to its unique structure. In the composite, the metal oxide may be an oxide containing at least one metal selected from the group consisting of V, Sn, Ru, Ir, Ta, Mn, Mo, and Ti. , And more specifically vanadium oxide such as vanadium pentoxide (V ₂ 0 ₅ ). When the vanadium oxide is used, the shape and the particle size of the vanadium oxide are not particularly limited. The shape of the vanadium oxide may vary depending on the kind of the carboxylic acid-based complexing agent. However, in order to improve the capacitance by increasing the contact area with the electrolyte, And may have a plate-like shape.

On the other hand, in the present invention, the term " plate-like " means that two surfaces facing each other are flat and the size in the horizontal direction is larger than the size in the vertical direction. f lake, scales, and the like. The composite further includes at least one doping element selected from the group consisting of a transition metal and an amphoteric metal element.

Specifically, the doping element may be doped to the metal oxide, the conductive inorganic material, or both in the composite. More specifically, within the crystal structure of the metal oxide or conductive inorganic material, or may be located through physical or chemical bonding to the surface of these materials. In particular, when the doping element is doped into the crystal structure of the metal oxide, the stability of the crystal structure can be improved, and when the conductive inorganic material is doped, the charge mobility between the doping element and the carbon- And the effect of improving the output characteristics can be further improved. The doping element specifically includes transition metal elements such as Mn, Cr, Cu, Mo, Ni, and Ti; Or amphoteric metal elements such as Al, Zn, Sn, Bi and the like, and any one or two or more of these elements may be used. In the case of any one or two or more elements selected from the group consisting of a transition metal including Mn, Cr, and Mo and a metal element having an amphiphilic nature of Al, the electric conductivity of the electrode material is increased due to an increase in charge mobility It may exhibit an excellent capacitance improving effect, more specifically, at least one of Mn and Al, and more specifically, Mn may be used. In addition, the effect of improving the electrostatic capacity due to doping can be further improved by optimizing the doping amount in the doping with the doping element. Specifically, the doping element may be contained in an amount of 0.1 to 30 atomic%, more specifically 0.1 atomic% or more, or 0.3 atomic / 3 or more, based on the total atomic weight of the constituent elements composing the complex , Not more than 20 atomic%, or not more than 10 atomic, or not more than 5 atomic%. More specifically, in the composite, the metal oxide is vanadium oxide, the conductive inorganic material is carbon nanotube, and the doping element is at least one of Al and Mn, the electrostatic capacity and output characteristics of the water- And the effect can be further improved when the content is optimized within the above combination. Meanwhile, the negative electrode material for a tap capacitor may be prepared by mixing a metal oxide, a conductive inorganic material, and a doping element raw material, followed by adding a carboxylic acid-based compounding agent to the mixture, And heat treating the resultant product (step 2). According to another embodiment of the present invention, there is provided a method of manufacturing a negative electrode material for a tap capacitor. Specifically, in the method of manufacturing a cathode material for a water capacitor, step 1 is a step of counteracting a metal oxide, a conductive inorganic material, a raw material of the doping element, and a carboxylic acid-based compounding agent.

The metal oxide and the conductive inorganic material are as described above, and may be used in an amount such that the content range of the metal oxide and the conductive inorganic material contained in the composite body described above is stratified. In the case of a metal oxide, hydrogen peroxide water; Or hydrochloric acid, in the case of a carbon-based material, or in a dispersion medium in which carboxymethyl sal is dispersed in a dispersion medium such as rosin and the like, respectively. As the raw material of the doping element, any one or two or more kinds of impurities selected from the group consisting of sulfate, nitrate, chloride, acetate and carbonate including a doping element may be used. In this case, same. More specifically, a sulfate including a doping element, more specifically, a sulfate including at least one of Mn and Al may be used. The amount of the raw material of the doping element may be determined within the range of the content of the doping element in the composite body as described above. In addition, the carboxylic acid-based compounding agent introduces a semi-functional group such as a carboxyl group, a hydroxyl group, or an amino group to the surface of the conductive inorganic material to provide a nucleation site for deposition of the metal oxide. As a result, the combination of the conductive inorganic material and the metal oxide promotes the formation of the complex of the metal oxide-conductive inorganic material, and when the metal oxide has the plate-like structure, the composite of the plate-like laminate structure is formed. In addition, the carboxylic acid-based compounding agent can form a chelate structure with metal ions in the electrolyte composition, and such a chelate structure can increase the layer discharge capacity of the battery. In addition, the carboxylic acid-based compounding agent can improve the stability of the metal ion, the improvement of the semisolidity, the suppression of the side reaction, and the reduction of the internal resistance. The carboxylic acid-based compounding agent is a compound having at least one carboxyl group in the molecule Specific examples of the compound include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, heptanoic acid, capryl ic acid, nonanoic acid, decanoic acid undecylenic acid, lauric acid, tridecyl ic acid, Monocarboxylic acids such as myristic acid, titanic decanoic acid and palmitic acid; oxalic acid, malonic acid, succinic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, Maleic acid, fumaric acid, glutaconic acid, traumatic acid, muconic acid, citric acid, isocitric acid, aconitic acid, isophthalic acid, terephthalic acid, and terephthalic acid; phthalic acid, isophthalic acid or terephthalic acid; Or a polyvalent carboxylic acid having three or more carboxyl groups such as melitic acid and the like, and any one or two or more of them may be used. An amino acid further containing an amino group together with a carboxyl group may be used. Specific examples thereof include glutamine, lysine, histidine, serine, threonine, tyrosine, cystine, cysteine, arginine, purine, glutamic acid, aspartic acid, asparagine or glutamine. Mixtures may be used.

Of these, acetic acid, citric acid, aspartic acid, or a mixture thereof may be used, and more specifically, L-aspartic acid may be used, considering the effect of a more excellent complexing agent. The carboxylic acid-based compounding agent may be used in an amount of 1 to 50 molar equivalents, more preferably 4 to 40 molar equivalents relative to 1 mol of the starting material of the doping element. The carboxylic acid-based compounding agent may be added in an amount of 200 to 1000 parts by weight based on 100 parts by weight of the metal oxide under the condition that the content ratio of the doping element to the raw material is clasified Specifically 200 to 500 parts by weight, and more particularly 300 to 400 parts by weight. When used in the above-mentioned content range, the effect of compounding agent can be exhibited without fear of occurrence of side reaction due to the residual of the polyanionic compounding agent. The carboxylic acid-based complexing agent may be solid or liquid, and may be added in the form of a solution or dispersion. More specifically, into a solution dissolved in a mixture of water and acid. At this time, the acid serves to assemble and maintain the nanoparticles in the form of a plate-like structure. Specifically, ascorbic acid, hydrochloric acid and the like can be used. In an amount of 5 to 20 mml per 100 ml of the water Can be used. _Wherein, a metal oxide, a conductive inorganic material, the material of the doping element material and banung of acid-based complexing agent is, be carried out by charging the common haphu acid-based complexing agent of the raw materials of the metal oxide, a conductive inorganic material, and the doping element .

At this time, the metal oxide, the conductive inorganic material, and the raw material of the doping element may be mixed according to a conventional method, and may further include a step for homogeneous mixing such as stirring. Further, after the metal oxide, the conductive inorganic substance, and the raw material of the doping element are mixed, an alcohol compound may be further added before the addition of the carboxylic acid-based compounding agent.

The alcohol-based compound plays a role in increasing the synthesis yield. Specifically, ethanol or the like can be used. The alcohol-based compound may be added in an amount of 100 to 200 parts by weight based on 100 parts by weight of the metal oxide, the conductive inorganic material, and the raw material of the doping element. The reaction of the metal oxide, the conductive inorganic substance, the doping element raw material and the carboxylic acid-based compounding agent is preferably 40 to 80 ^° C, more specifically 60 to 80 ^° C, 70 < 0 ^> C. The performance can be performed with excellent efficiency without worrying about overaction or unresponsiveness in the above temperature range.

Further, a process such as reflux may be selectively performed in order to increase the anti-warping efficiency. As a result of the reaction of the metal oxide, the conductive inorganic substance, the raw material of the doping element and the carboxylic acid-based compounding agent, the reactant is precipitated.

With respect to the precipitated semipermeable material, a separation process according to a conventional method such as centrifugation and a process for removing impurities using a washing solvent such as water or ethanol can be performed on the separated semipermeable material.

In addition, a drying process for the separately washed washed water may optionally be further performed. The drying process may be carried out using a conventional method, but in the present invention, a freeze drying method may be used for maintaining the shape of the composite structure of the plate-like structure and preventing aggregation during drying. Next, step 2 is a step of preparing a negative electrode material by heat-treating the antimony material obtained in step 1 above.

The reaction product obtained in the step 1 is a state in which the raw material of the doping element is bonded to the composite in which the metal oxide is formed by bonding with the conductive inorganic material via the functional group derived from the carboxylic acid compound. A doped element is doped in an elemental state to obtain a negative electrode material containing a composite of a plate-like laminate structure in which a conductive inorganic material is interposed. The heat treatment process may be performed ^at 250 to 350 ^° C, more specifically, at 270 to 300 ^° C. The negative electrode material can be obtained at a high efficiency without fear of generation of a side reaction depending on the reaction temperature and the reaction temperature. The negative electrode material produced according to the above-described production method has a laminate structure of a plate-shaped composite of the metal oxide and the conductive inorganic material, The accessibility of the electrolyte is easy and the charge mobility between the doping element and the conductive inorganic material is increased by doping with the doping element so that the capacitance and the output characteristic can be remarkably improved when applied to the cathode of the capacitor. Accordingly, according to another embodiment of the present invention, there is provided a composition for forming a negative electrode for a capacitive capacitor including the negative electrode material, and a negative electrode for a tap capacitor manufactured using the same

Specifically, the composition for forming a negative electrode for a tap capacitor includes the negative electrode material described above, and may further include at least one of a binder and a conductive material.

The conductive material is used for imparting conductivity to the negative electrode. The conductive material may be used without any particular limitation as long as it has an electronic conductivity without causing chemical change. Specific examples thereof include carbonaceous materials such as natural wood chips or artificial wood chips or carbonaceous materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, summer black and carbon fiber. One or more impurities may be used. More specifically, carbon black or acetylene black can be used. The conductive material may be included in an amount of 10 to 30 parts by weight based on 100 parts by weight of the negative electrode material. In addition, the binder plays a role of enhancing adhesion between the negative electrode particles and adhesion between the negative electrode material and the negative electrode of the current collector. Specific examples include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethylcellulose Polypropylene, ethylene-propylene-diene polymer (EPDM), sulphonated-EPDM, polyvinyl pyrrolidone, polyvinyl pyrrolidone, polyvinyl pyrrolidone, polyvinyl pyrrolidone, Styrene-butadiene rubber (SBR), fluorine rubber, and various copolymers thereof. One or more of these may be used. Among them, a binder of a fluorine-based polymer such as PVDF or PTFE which can exhibit higher stability with respect to the electrolyte is used . The binder may be included in an amount of 10 to 20 parts by weight based on 100 parts by weight of the negative electrode material. In addition, the negative electrode in the tap water capacitor can be produced by a conventional method except that the composition for forming an anode is used. For example, the composition for forming an anode may be coated on a current collector such as copper aluminum, nickel, or stainless steel, followed by pressing and drying. According to another embodiment of the present invention, there is provided an electrochemical device including the negative electrode. The electrochemical device may be specifically a capacitor, and more specifically, may be a tap capacitor.

Specifically, the water storage capacitor includes an anode and a cathode, a separator interposed between the anode and the cathode, and an electrolyte, and the cathode is as described above.

The constitution and the manufacturing method of the other water capacitors can be performed according to a usual method, and a detailed description thereof will be omitted. The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

Example 1

0.9 g of V ₂ O ₅ , 30 ml of deionized water and 20 ml of H ₂ O ₂ were added to an isometric flask and stirred. 6 g of CNT (6 g of CNT) is added to a dispersion of CMT (carboxymethylcellulose) in 30 ml of deionized water. The CNT content in the dispersion is 5 wt. , CNT diameter = 9 to 11 nm) was added to the dispersion, and 0.5 mol of A1 ₂ (SO ₄ ) ₃ was added as a doping element raw material. After addition of 100 ml of ethanol, the resultant mixture a, L- aspartic acid, 20ml (4 mol / V source material 1 on a molar basis of the doping element ₂ 0 ₅ based on 100 parts by weight corresponding to 400 parts by weight) ^", a solution prepared by adding the common de-ionized water and 70ml 6N HC1 5ml dropwise, and the reflux for 12 hours at 60 ^° C Respectively. The resulting precipitate was separated by centrifugation. The impurities were removed by washing with deionized water and ethanol. Freeze dried for 3 days to obtain a result of water, for 12 hours heat treatment at 270 ^° C temperature condition in the furnace ryubeu, a negative electrode material A1 is doped for the metal oxide -CNT complex of V ₂ 0 ₅ was prepared. Example 2

In Example _{_{_{1 A1 2 (S0 4) 3}}} 0.5謹ol instead, and is carried out in the same manner as in Example 1 except for the use of MnS0 ₄ lmrol a, V ₂ 0 ₅ of the metal oxide composite -CNT A negative electrode material doped with Mn was prepared. Example 3

In Example _{_{_{1 A1 2 (S0 4) 3}}} 0.5画1 instead of the Cu (N0 ₃₎ ₂ 1 to and is carried out in the same manner as in Example 1 except for the use of瞧, the V ₂ 0 ₅ A cathode material doped with Cu for the metal oxide-CNT composite was prepared. Example 4

0.9 g of V ₂ O ₅ and 20 ml of deionized water, 30 m < ₂ > H ₂ O ₂ were added to an isometric flask and stirred. In 60 ml of deionized water, 60 g of graphene oxide (60 g of the graphene oxide is added to the dispersion in which the graphene oxide is dispersed in water, wherein the content of graphene oxide contained in the dispersion to be added is 60 g the addition of peroxide concentration _{= 5} wt _¾), and the mixture was added heunhap fall MnS0 ₄ lmm as doping element raw material. after the addition of ethane added to the 100ml, L- aspartic acid results in common compound of 20ml, 70ml of deionized water and 6N HCl was added dropwise and refluxed for 12 hours at 60 ^° C. The resulting precipitate was separated by centrifugation and washed with deionized water and ethanol to remove impurities. after the freeze-drying the obtained water for three days, for 12 hours at 270 ^° C temperature in the tube furnace heat treatment, the metal oxide V ₂ 0 ₅ - Yes for the pin Mn complex The doped negative electrode material was produced. Comparative Example The doping element in Example 1 and the negative electrode material of Example 1 is performed in the same way as in, non-metal oxides, doped ^ ₂ 0 ₅ -CNT composite form, except that the unused raw material was used to. Comparative Example 2

0.9 g of V ₂ O ₅ , 30 ml of deionized water and 20 ml of H ₂ O ₂ were added to an isometric flask and stirred. MnS04 ₁ mm as a doping element raw material was added thereto and mixed. After addition of 100 ml of ethanol, a solution prepared by mixing 20 ml of L-aspartic acid, 70 ml of deionized water and 5 ml of 6N HCl was added dropwise to the resulting mixture and refluxed at 60 ^° C for 12 hours. The resulting precipitated material was separated by a centrifuge and washed with deionized water and ethanol to remove impurities. The resulting product was lyophilized for 3 days and then heat treated in a tube furnace at 27 C C for 12 hours to prepare a cathode material doped with Mn to a metal oxide of V ₂ O ₅ . Comparative Example 3 1.8g deunggeun Mn0 _2, deionized water and the flask was 30ml, stirring the ¾0 ₂ 20ml. 6 g of CNT (6 g of CNT) is added to a dispersion of CMT (carboxymethylcellulose) in 30 ml of dehydrogenated water (CNT concentration in the dispersion = 5% by weight) ) And a CNT diameter of 9 to 11 nm) were dispersed in the dispersion solution. After further added to 100ml of ethanol, 20ml of L- aspartic acid, deionized water and 70ml of 6N HCl 5ml dropwise a solution prepared ^'traces were combined and refluxed at 60 ^° C for 12 hours was performed on the traces of the compound results. The resulting precipitated material was separated by a centrifuge and washed with deionized water and ethanol to remove impurities. The resulting product was freeze-dried for 3 days and then heat-treated in a tube furnace at a temperature of 270 ^° C for 12 hours to prepare a negative electrode material of an undoped Mn metal oxide-CNT composite. Experimental Example 1

For the vanadium oxide used in Examples 1 and 2, X-ray photoelectron Spectroscopic analysis (XRD) was performed and the crystal structure was observed using a scanning electron microscope (SEM). The results are shown in Figs. 1A to 1C and Figs. 2A to 2C, respectively.

FIG. 1A is a graph showing an XRD analysis result of the vanadium oxide used in Example 1, FIG. 1B is an SEM photograph, and FIG. 1C is an enlarged view of a circled portion of FIG.

2A is a graph showing an XRD analysis result of the vanadium oxide used in Example 2, FIG. 2B is an SEM photograph, and FIG. 2C is an enlarged view of the circle display portion of FIG. 2B.

As shown in FIGS. 1A to 1C and FIGS. 2A to 2C, it can be seen that the vanadium oxide used in Examples 1 and 2 has a plate-like structure. Each of the cathode materials prepared in Examples 1 to 3 and Comparative Example 1 was observed by SEM. The results are shown in Figs. 3A to 6, respectively.

3A is an SEM photograph of a composite of the vanadium oxide-carbonaceous material prepared in Example 1 at various magnifications, and FIGS. 4A to 4C are cross-sectional views of the composite of the vanadium oxide-carbonaceous material prepared in Example 2 SEM photographs were taken at various magnifications. 5 and 6 are SEM photographs of the composite of the vanadium oxide-carbonaceous material prepared in Example 3 and Comparative Example 1, respectively.

As a result of observation, it can be confirmed that the composite of the vanadium oxide-carbonaceous materials of Examples 1 to 3 and Comparative Example 1 has a structure in which a carbonaceous substance is interposed between vanadium oxides in a plate form and laminated. Each of the cathode materials prepared in Examples 1 and 2 was observed with an electron microscope, and elemental analysis was performed using EDS. The results are shown in FIGS. 7 and 8, respectively.

As a result of the analysis, it was confirmed that the anode materials of Examples 1 and 2 were doped with a doping element of Al or Mn to the vanadium oxide-carbonaceous material composite of the plate-like laminated structure (A1 doping amount in Example 1 (Based on total atomic content): 0.3 atomic ¾, Mn doping amount in Example 2 (based on the total atomic content of the composite): 1.08 Atomic experiment example 2

CV graphs were measured by cyclic voltammetry (CV) for each of the negative electrode compositions prepared in Examples 1, 2 and 4 and Comparative Examples 2 and 3.

Specifically, PVDF as a negative electrode material, carbon black and binder prepared in Examples 1, 2 and 4 and Comparative Examples 2 and 3 were mixed at a weight ratio of 7: 2: 1 to prepare a composition for forming an anode , Applied to a glacier carbon electrode (GCE), vacuum-dried, and dried at 70 ^° C for 24 hours. The prepared electrode was impregnated with ₁ M Li ₂ S0 ₄ electrolyte, stabilized, and subjected to cyclic scanning potential test using a platinum counter electrode and an SCE reference electrode. Voltage range -1. 1 to -0.2 V and a potential scanning speed of 10 mV / s.

The capacitance per unit mass is largely dependent on the vanadium oxide content and the specific surface area of the cathode material, and can be calculated by dividing the current value appearing on the circulating preform by the scanning speed and the mass of the electrode active material. The results are shown in Figs. 9 to 13 and Table 1.

[Table 11

2 ^nd 405.08 49. 18 488.08 57.40 283.71 30. 19 81.87 3.53 81.87 3.53

3 ^rd - - - ᅳ 273. 16 28.58 77.85 3.42 77.85 3.42

₄ th - - 1 - 265.25 27.35 74.62 3.31 74.62 3.31

5 ^th 330.65 39.92 405.08 48. 14 257.27 26.50 64.06 3. 17 64.06 3. 17

In Table 1, " - " means not measured. As a result of the measurement, the negative electrode materials of Examples 1, 2, and 4 exhibited a high energy density with high capacitance as compared with Comparative Examples 2 and 3. Among them, Examples 1 and 2 including CNT as a conductive inorganic material showed a high energy density of more than 50 Wh / kg together with a high electrostatic capacity of 450 F / g or more due to high electrical conductivity of CNT, and 300 F / g and the electrostatic capacity and energy density of 30 Wh / kg or more. The excellent electrostatic capacity and energy density characteristics are due to the fact that the specific surface area of the negative electrode material of Examples 1 and 2 greatly increased with the layered structure. On the other hand, Example 4, which includes graphene instead of CNT, exhibits relatively low capacitance and energy density due to the difference in the low charge transfer capacity and conduction path compared to Examples 1 and 2 .

In the case of Comparative Example 2 which does not include a conductive inorganic substance such as CNT, since the charge transporting ability is lowered due to the absence of a conductive bridge to be present between the particles, The capacitance and energy density were shown, and after 5 cycles, the difference in capacitance and energy density was greater.

Also, in Comparative Example 3 including only a complex of a metal oxide and a conductive inorganic material without doping elements, the electrostatic capacity and the energy density significantly decreased due to the decrease of charge mobility compared with the embodiment including the doping element. Experimental Example 3 In the same manner as in Experimental Example 2, electrodes were prepared using the negative electrode materials of Examples 1 to 3 and Comparative Example 1, and each of the prepared electrodes was impregnated with ₁ M Li ₂ S0 ₄ electrolyte, stabilized The output characteristics were evaluated under the conditions of 1 ~ 20kW / kg, 1 ~ 30A / g at the voltage range of -1.2-0.2V using the platinum counter electrode and the SCE reference electrode. The results are shown in Fig.

Experimental results show that the negative electrode materials of Examples 1 to 3 including the composite material of the vanadium oxide-carbon based material doped with Cii, Al, or Mn have better output characteristics than the negative electrode material of the non- Respectively. From these results, it can be seen that the output characteristics of the electrode material can be further improved by doping the vanadium oxide-carbon composite material. Experimental Example 4

Li ₂ SO ₄ electrolyte was vacuum-impregnated and stabilized in each of the electrodes including the cathode materials of Examples 1 to 3 and Comparative Example 1 prepared above, and then, using the platinum counter electrode and the SCE reference electrode, A potential experiment was performed. At a voltage range of -1.2 to -0.2 V, and at a potential scanning speed of 10 mV / s. The results are shown in Table 2 below.

[Table 2]

As a result, Examples 1 to 3 exhibited improved electrostatic capacitances as compared with Comparative Example 1, and Examples 1 and 2 doped with Al or Mn exhibited greatly increased capacitances of more than 350 F / g. On the other hand, in the case of Example 3 doped with Cu, the electrostatic capacity was reduced as compared with Examples 1 and 2 due to the relatively low charge mobility despite the metal doping.

Claims

[Claims]

[Claim 1]

A complex of a metal oxide-conductive inorganic material including a metal oxide and a conductive inorganic material combined with the metal oxide,

Wherein the composite is doped with at least one doping element selected from the group consisting of a transition metal and an amphoteric metal element.

[Claim 2]

The method according to claim 1, wherein the metal oxide has a plate-

Wherein the composite has a plate-like laminate structure in which a conductive inorganic material is interposed between a plurality of the plate-shaped metal oxides.

[Claim 3]

The negative electrode material for a capacitive capacitor according to claim 1, wherein the composite is doped with at least one doping element selected from the group consisting of Mn, Cr, Cu, Mo, Ni, Ti, Al, Zn, Sn and Bi.

Claim 4

The negative electrode material for a capacitive capacitor according to claim 1, wherein the doping element is contained in an amount of 0.1 to 30 atomic% with respect to the total content of the elements constituting the composite.

[Claim 5]

Wherein the metal oxide is an oxide containing at least one metal selected from the group consisting of V, Sn, Ru Ir, Ta, Mn, Mo, and Ti.

[Claim 6]

The conductive inorganic material according to claim 1, wherein the conductive inorganic material comprises at least one selected from the group consisting of carbon-based materials and Mxene. Cathode material for water capacitors

[7]

The conductive inorganic material according to claim 1, wherein the conductive inorganic material comprises one or two or more carbon-based materials selected from the group consisting of carbon nanotubes, carbon nanofibers, carbon nanorods, vapor growth carbon fibers, graphene, , Cathode materials for water capacitors.

8.

The negative electrode material for a capacitive capacitor according to claim 1, wherein the metal oxide is contained in an amount of 1 to 30 parts by weight based on 100 parts by weight of the conductive inorganic material.

[Claim 9]

The method of claim 1, wherein the metal oxide comprises vanadium oxide, the conductive inorganic material comprises carbon nanotubes, and the composite is doped with at least one of Al and Mn. .

Claim 10

Mixing a metal oxide, a conductive inorganic material and a raw material of a doping element, and then adding a carboxylic acid-based compounding agent to the mixture; And

The method of manufacturing a cathode material for a watercapped capacitor according to claim 1, comprising the step of heat treating the resultant anode material.

Claim 11

11. The method of claim 10, wherein the source material of the doping element comprises at least one selected from the group consisting of sulfates, nitrates, chlorides, acetates, and carbonates including doping elements. Method of manufacturing materials ᅳ

Claim 12 11. The method of manufacturing a cathode material for a capacitive capacitor according to claim 10, wherein the raw material of the doping element is a sulfate containing at least one of Mn and Al.

Claim 13

The method for producing a negative electrode material for a capacitive capacitor according to claim 10, wherein the carboxylic acid-based complexing agent is selected from the group consisting of a monocarboxylic acid, a dicarboxylic acid, a polyfunctional carboxylic acid having three or more functional groups, and an amino acid.

14.

11. The method of claim 10, wherein the carboxylic acid-based complexing agent is selected from the group consisting of L-aspartic acid, acetic acid, citric acid, and a mixture thereof.

[15]

11. The method of manufacturing a cathode material for a capacitive capacitor according to claim 10, wherein an alcoholic compound is further added before the addition of the carboxylic acid-based complexing agent after mixing of the metal oxide, the conductive inorganic substance and the doping element raw material.

Claim 16

11. The method of claim 10, wherein the carboxylic acid-based complexing agent is charged into a solution dissolved in a mixture of water and acid.

[Claim 17]

11. The method of claim 10, further comprising lyophilizing the resultant blank before the heat treatment.

Claim 18

The method of claim 10, wherein the heat treatment is performed ^at 250 to 350 ^° C.

[19]

A negative electrode for a water-cooled capacitor comprising a negative electrode material according to any one of claims 1 to 9.

[20]

A water-containing capacitor comprising a negative electrode material according to any one of claims 1 to 9.