KR101220036B1 - Electrode for electrochemical device, method for fabricating the same and electrochemical device - Google Patents

Abstract

The present invention relates to an ultra-high capacity electrochemical device electrode, a manufacturing method and an electrochemical device formed using a chemical impregnation method, the electrochemical device electrode of the present invention comprises a current collector; And an active material layer containing metal hydroxide nanowires having one end portion in a longitudinal direction thereof facing upward on the current collector. Accordingly, the supercapacitor of the present invention has characteristics of high power storage capacity, high power, and high energy density.

Description

Electrochemical device electrode, manufacturing method and electrochemical device therefor {Electrode for electrochemical device, method for fabricating the same and electrochemical device}

The present invention relates to an electrochemical device electrode, a method for manufacturing the same, and an electrochemical device, and more particularly, to an electrochemical device electrode having a high capacity, which is formed using a chemical impregnation method, a method for manufacturing the same, and an electrochemical device.

As electrochemical devices, supercapacitors are recently attracting attention due to the rapid development of electric vehicles and electronic technologies and the need for a powerful energy source. This is because a role as an energy storage source capable of instant charging and discharging is required.

These supercapacitors are broadly classified into Electric Double Layer Capacitors (EDLC) using carbon (particles or fibers) having a high specific surface area for electrode materials, and Pseudocapacitors composed of metal oxides or conductive polymers. can do.

Electric double layer capacitors exhibit very good lifespan characteristics by utilizing physical adsorption and desorption of ions. However, since charges accumulate only on the electrical double layer on the surface, there is a disadvantage that the storage capacity is lower than that of the metal oxide-based or electrically conductive polymer-based supercapacitor using the Faraday reaction.

Metal oxide-based supercapacitors are supercapacitors using metal oxides having multiple valences capable of redox. The electrode active material of the metal oxide supercapacitor is required to have a high specific surface area at the interface of the electrode because the ions and electrons required for redox are rapidly moved from the electrolyte and the electrode during charging and discharging, and the electrode active material has a high electrical conductivity. Is required. However, metal oxide-based supercapacitors have a narrow operating voltage range, which results in a smaller energy density than EDLC.

In addition, similar supercapacitors using metal oxides, especially ruthenium oxide (RuOx) as electrode materials, have a capacity of about 3 to 4 times larger than EDLC. However, since expensive metal oxides are used as electrode active materials, development of new electrode active material materials that can lower production costs is urgently required.

In this regard, conductive polymers having low production cost, high conductivity, and fast charge / discharge capability are attracting attention as a substitute material for metal oxides, but have a disadvantage in that they are less stable in charging and discharging processes than metal oxides. have.

An object of the present invention for solving the above problems is to provide an ultra-high capacity electrochemical device electrode, a method for manufacturing the same, and an electrochemical device formed using a chemical impregnation method.

In order to solve the technical problem of the present invention, an aspect of the present invention provides an electrochemical device electrode. The electrochemical device electrode is a current collector; And an active material layer containing metal hydroxide nanowires having one end portion in a longitudinal direction thereof facing upward on the current collector.

The metal hydroxide nanowires are N (OH) ₂ · mH ₂ O, M (OH) ₂ · mH ₂ O, and [N (OH) ₂ ] _1-x [M (OH) ₂ ] _x · mH ₂ O. It contains two kinds of metal hydroxides selected from the group consisting of, wherein N and M are different kinds of metals selected from the group consisting of Ca, Mg, Fe, Co, Ni, Cu and Zn, 0 <X <1 , m may be 0 to 10, preferably N and M may be Ni and Co, respectively.

In addition, the electrode may further include a conductive carbon film interposed between the current collector and the active material layer.

The active material layer may further contain a conductive carbon material, and the conductive carbon material may be at least one selected from the group consisting of carbon nanotubes, activated carbon, graphene, and graphene oxide. have.

In addition, the electrochemical device electrode of the present invention; And a _{N (OH) 2 · mH 2} O, M (OH) 2 · mH 2 O, and _{[N (OH) 2] 1} -x [M (OH) 2] x · mH 2 O onto the current collector It contains two kinds of metal hydroxides selected from the group consisting of, wherein N and M are different kinds of metals selected from the group consisting of Ca, Mg, Fe, Co, Ni, Cu and Zn, 0 <X <1 , m may include an active material layer of 0 to 10.

In addition, another aspect of the present invention provides a method of manufacturing an electrochemical device electrode. The method includes preparing a metal precursor solution containing a first metal salt, a second metal salt having a metal different from the first metal salt, and a base material; And impregnating a current collector in the aqueous metal precursor solution to form metal hydroxide nanowires having one end portion in a longitudinal direction thereof upward.

In the forming of the metal hydroxide nanowires, the pH of the metal precursor aqueous solution may be 7 to 14.

Forming the metal hydroxide nanowires may be performed at a temperature of 50 ℃ to 100 ℃.

Forming the metal hydroxide nanowires may be performed for 30 minutes to 3 hours.

The method may further include forming a conductive carbon film on the current collector before the forming of the metal hydroxide nanowires.

The metal precursor aqueous solution may further contain a conductive carbon material.

The method may further include forming a metal hydroxide nucleus on the current collector by impregnating a current collector in the aqueous metal precursor solution before forming the metal hydroxide nanowires.

The forming of the metal hydroxide nucleus on the current collector may further include taking out and drying the current collector impregnated in the metal precursor aqueous solution.

In addition, the method of manufacturing an electrochemical device electrode of the present invention contains a first metal salt of M (X) ₂ · mH ₂ O, a second metal salt of N (Y) ₂ · nH ₂ O, and a base material, the N and M is deulyigo metal of different types selected from the group consisting of Ca, Mg, Fe, Co, Ni, Cu and Zn, X and Y are independently selected, Cl ^-, nO ₃ ^- and CHOO ^- the group consisting of M is 0 to 10 to prepare an aqueous metal precursor solution; And impregnating a current collector in the aqueous metal precursor solution to form an active material layer on the current collector.

In addition, the electrochemical device of the present invention includes a first electrode including a current collector and a first active material layer on the current collector; A second electrode including a current collector and a second active material layer on the current collector; A separator interposed between the first electrode and the second electrode; And an electrolyte solution for ion exchange, wherein the first active material layer of the first electrode contains a metal hydroxide nanowire having one end portion thereof in a length direction thereof facing upward.

As described above, according to the present invention, the electrochemical device electrode of the present invention contains the current collector and the metal hydroxide nanowire with one end portion in the longitudinal direction of the current collector toward the top, thereby improving the contact area with the electrolyte. Accordingly, the capacitance and output of the electrochemical device can be improved. In addition, an electrochemical device electrode having a conductive carbon film formed on a current collector and then forming a metal hydroxide nanowire thereon has a high energy density with improved capacitance and high output characteristics.

1 is a schematic cross-sectional view for describing an electrochemical device according to an embodiment of the present invention.
2 is a flowchart illustrating a method of manufacturing an electrode of an electrochemical device according to an embodiment of the present invention.
3 is an electron microscope image of an electrode manufactured according to an embodiment of the present invention.
4A to 4D are graphs illustrating electrochemical characteristics of a supercapacitor to which an electrode manufactured according to an embodiment of the present invention is applied.
5A and 5B are electron microscope images of electrodes prepared according to an embodiment of the present invention.
6A to 6D are graphs illustrating electrochemical characteristics of a supercapacitor to which an electrode manufactured according to an embodiment of the present invention is applied.

The features and acts of the present invention will become apparent from the embodiments described below with reference to the accompanying drawings.

DETAILED DESCRIPTION The detailed description set forth below in connection with the appended drawings is made with the intention of describing preferred embodiments of the invention and does not represent the only forms in which the invention may be practiced. It should be noted that the same and equivalent functions included in the spirit or scope of the present invention may be achieved by other embodiments. In addition, certain features disclosed in the drawings are enlarged for ease of description, and the drawings and their components are not necessarily drawn to scale. However, those skilled in the art will readily understand these details. In addition, the same reference numerals are used for the same components in the drawings, and redundant description of the same components is omitted.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic cross-sectional view for describing an electrochemical device according to an embodiment of the present invention, the electrochemical device according to an embodiment of the present invention may be a super capacitor.

Referring to FIG. 1, an electrochemical device according to an exemplary embodiment includes a first electrode 10 and a second electrode 20, and a first electrode 10 and a second electrode 20 disposed opposite to each other. Electrolyte (not shown in figure) between the separator 30, the 1st electrode 10, and the separator 30, and between the separator 30 and the 2nd electrode 20 is included.

The first electrode 10 includes a current collector 11 and a first active material layer 13 on the current collector 11. In addition, the conductive carbon film 12 may be further included between the current collector 11 and the first active material layer 13. The first electrode 10 may be an anode.

In this case, the current collector 11 may be Fe, Cu, Ti, Ni, Pt, Al, Au and alloys thereof. In addition, the current collector 11 may be any one selected from the group consisting of a conductive polymer and a conductive oxide. In addition, the current collector 11 may be a porous or non-porous foam.

In addition, the conductive carbon film 12 may be at least one selected from the group consisting of carbon nanotubes, activated carbon, graphene, and graphene oxide. However, the conductive carbon film 12 may be omitted.

In addition, the first active material layer 13 contains metal hydroxide nanowires whose one end in the longitudinal direction is directed upward, that is, in the direction opposite to the current collector 11 or in the direction of the second electrode 20. As such, since the first active material layer 13 contains nanowires, the area of the first active layer 13 in contact with the electrolyte may be improved, and the capacitance of the electrochemical device may be improved. Such metal hydroxide nanowires include two kinds of metal dihydroxides having different kinds of metals.

In more detail, the metal hydroxide nanowires are N (OH) ₂ · mH ₂ O, M (OH) ₂ · mH ₂ O, and [N (OH) ₂ ] _1-x [M (OH) ₂ ] contains two kinds of metal hydroxide is selected from the group consisting of _x · mH ₂ O. In this case, N and M may be different kinds of metals selected from the group consisting of Ca, Mg, Fe, Co, Ni, Cu, and Zn, and specifically, N and M may be Ni and Co, respectively. In addition, X may be 0 <X <1, m may be 0 to 10, specifically m may be 6 to 7.

In addition, the metal hydroxide nanowires of the first active material layer 13 may further include a conductive carbon material for improving the charge capacity of the electrochemical device and the electrical conductivity of the electrode according to the embodiment of the present invention. The conductive carbon material may be at least one selected from the group consisting of carbon nanotubes, activated carbon, graphene, and graphene oxide. The conductive carbon material is preferably 15 wt% or less of the total composition of the first active material layer 13. When the conductive carbon material exceeds 15wt% of the total composition of the first active material layer 13, the conductive carbon material reduces the area where the metal hydroxide nanowire is in contact with the electrolyte, thereby reducing the capacitance of the supercapacitor. Because you can.

The second electrode 20 includes a current collector 21 and a second active material layer 22 on the current collector 21. The second electrode 20 may be a cathode.

The current collector 21 of the second electrode 20 may be all made of a conductive material. For example, the current collector 21 of the second electrode 20 may be made of any one of a metal foil, a metal mesh, and a conductive polymer compound.

In addition, the negative electrode active material 22 of the second electrode 20 may be any conductive material. For example, the negative electrode active material 22 of the second electrode 20 may be made of a conductive carbon material, a conductive metal, and a conductive oxide.

The material that can be used as the separator 30 may be a microporous polypropylene or polyethylene membrane, a porous glass fiber tissue or a combination of polypropylene and polyethylene.

The electrolyte is an aqueous electrolyte having basic properties, and may be, for example, an alkaline electrolyte such as aqueous potassium hydroxide (KOH) solution. The use of an acidic electrolyte is not preferred because it can cause dissolution of the electrodes 10 and 20.

2 is a flowchart illustrating a method of manufacturing an electrode of an electrochemical device according to an embodiment of the present invention.

Referring to FIG. 2, first, an aqueous metal precursor solution is prepared (S1).

In this case, the aqueous metal precursor solution contains a first metal salt, a second metal salt having a metal different from the first metal salt, and a base material.

The first metal salt may be M (X) ₂ · mH ₂ O, and the second metal salt may be N (Y) ₂ · mH ₂ O. In this case, the N and M is Ca, Mg, Fe, Co, Ni, deulyigo metal of different types selected from the group consisting of Cu and Zn, X and Y are independently selected, Cl ^-, NO ₃ ^- and CHOO ^- may be selected from the group consisting of which, m can be 0 to 10. In addition, the molar ratio of the first metal salt and the second metal salt in the aqueous metal precursor solution, that is, the molar ratio of N and M is preferably 1: 9 to 9: 1.

The base material is added to the aqueous metal precursor solution to adjust the pH of the aqueous metal precursor solution to between 7 and 14. Preferably, the pH of the aqueous metal precursor solution may be adjusted to 10 to 13 by adjusting the amount of the base material to be added. This means that the aqueous metal precursor solution initially exhibits an acidity of less than pH 7. It is possible to synthesize the metal hydroxide nanowires using the aqueous metal precursor solution only in neutral or basic conditions, and the metal hydroxide at pH 10 to 13 of the aqueous metal precursor solution. This is because the production rate of nanowires is high.

As the base material, any basic material may be used. For example, ammonia may be used.

In addition, the metal precursor aqueous solution may further include a conductive carbon material. The conductive carbon material may be at least one selected from the group consisting of carbon nanotubes, activated carbon, graphene, and graphene oxide.

After preparing the metal precursor aqueous solution, a current collector may be prepared, and a conductive carbon film may be formed on the current collector (S2).

The current collector may be Fe, Cu, Ti, Ni, Pt, Al, Au and alloys thereof. In addition, the current collector may be any one selected from the group comprising a conductive polymer and a conductive oxide, and may be a porous or non-porous foam.

In addition, the conductive carbon film may be at least one selected from the group consisting of carbon nanotubes, activated carbon, graphene and graphene oxide.

The conductive carbon film on the current collector can be formed through various methods. For example, the conductive carbon film may be formed on the current collector through a carbonization reaction of a polymer precursor, or may be formed by applying a carbon material paste containing a dispersant to the current collector.

However, the forming of the conductive carbon film may be omitted.

After forming the conductive carbon film, a metal hydroxide nucleus may be formed on the current collector on which the conductive carbon film is formed (S3).

The metal hydroxide nucleus serves as a seed material for easily forming the metal hydroxide nanowires, and may be formed by impregnating a current collector having the conductive carbon film in an aqueous metal precursor solution for 10 to 30 minutes. have. At this time, the aqueous metal precursor solution may be maintained at 50 ℃ to 100 ℃.

When the metal hydroxide nucleus is formed, the current collector may be taken out and dried, but the step of removing and drying the current collector may be omitted.

After the metal hydroxide nucleus is formed, metal hydroxide nanowires are formed on a current collector using the metal hydroxide nucleus (S4).

The current collector on which the metal hydroxide nucleus is formed is impregnated in an aqueous metal precursor solution having a pH of 7 to 14, thereby forming an active material layer containing metal hydroxide nanowires. Preferably, the pH of the aqueous metal precursor solution may be maintained at 10 to 13. This is because the metal hydroxide nanowires are generated only when the pH of the aqueous metal precursor solution is neutral or base, and the production rate of the nanowires of the metal hydroxide is high when the pH is 10 to 13.

In addition, in order to obtain an appropriate thickness of the active material layer, the impregnation of the current collector is preferably performed for 30 minutes to 3 hours. When the current collector is impregnated in the aqueous metal precursor solution for 30 minutes or less, the metal hydroxide nanowires may not be sufficiently generated, thereby degrading the performance of the supercapacitor, which is an electrochemical device. In addition, when the current collector is impregnated in the metal precursor aqueous solution for 3 hours or more, the amount of the nanowires produced increases and the thickness of the active material layer is increased. When the active material layer is thick, the internal resistance of the electrode of the electrochemical device is increased, thereby degrading the performance of the supercapacitor, which is an electrochemical device.

In addition, the metal precursor aqueous solution is preferably maintained at 50 ℃ to 100 ℃. If the temperature of the metal precursor solution is less than 50 ℃ due to the low temperature of the hydroxide ions and metal ions present in the solution is difficult to synthesize the metal hydroxide on the surface of the current collector, the temperature of the metal precursor solution is 100 ℃ This is because when the water is a solvent of the aqueous metal precursor solution, the metal precursor aqueous solution may evaporate before the metal hydroxide having a high surface area is formed on the surface of the current collector.

The metal hydroxide nanowires are N (OH) ₂ · mH ₂ O, M (OH) ₂ · mH ₂ O, and [N (OH) ₂ ] _1-x [M (OH) ₂ ] _x · mH ₂ O. It contains two kinds of metal hydroxides selected from the group consisting of, wherein N and M are different kinds of metals selected from the group consisting of Ca, Mg, Fe, Co, Ni, Cu and Zn, 0 <X <1 , m may be 0 to 10. For example, when Co is used as N and Ni is used as M, the metal hydroxide nanowires may be selected from Co (OH) ₂ · 6H ₂ O, Ni (OH) ₂ · 6H ₂ O, and [Co (OH) ₂ ]. [Ni (OH) _2] · may be two kinds of metal hydroxide selected from the group consisting of 6H ₂ O.

In the above, a method of forming metal hydroxide nanowires after forming a metal hydroxide nucleus has been described. However, the present invention is not limited thereto, and the current collector is impregnated with an aqueous metal precursor solution to form a conductive carbon film on the current collector. It is also possible to simultaneously form a metal hydroxide nucleus and a metal hydroxide nanowire on the conductive carbon film.

After the metal hydroxide nanowires are formed, a current collector on which the metal hydroxide nanowires are formed is dried (S5).

The drying method can be carried out using various methods. For example, it may be left to dry in an ambient temperature atmosphere, or may be dried by evaporating the solvent of the precursor solution by applying heat.

Hereinafter, preferred electrode preparation examples are provided to aid the understanding of the present invention. However, the following electrode preparation examples are merely to aid the understanding of the present invention, the present invention is not limited by the following electrode preparation examples.

Electrode Preparation Example 1

CoCl ₂ and Ni (NO ₃ ) ₂ · 6H ₂ O are used as precursors of cobalt and nickel, so that the molar ratio of nickel and cobalt ions is 3: 1 so that 0.1M CoCl ₂ and 0.1M Ni (NO ₃ ) ₂ 6H ₂ O was dissolved in an aqueous solution, and ammonia was added to prepare an aqueous solution of cobalt and nickel ions having a pH of 12.

The aqueous solution was impregnated with a stainless steel substrate as a conductive current collector and coated at a temperature of 343K for 1 hour to prepare cobalt-nickel hydroxide nanowires, and dried to prepare an electrode of an electrochemical device.

Electrode Preparation Example 2

An electrode of an electrochemical device was manufactured in the same manner as in Preparation Example 1, except that the molar ratio of nickel and cobalt ions was 2: 1.

<Electrode Preparation Example 3>

An electrode of an electrochemical device was manufactured in the same manner as in Preparation Example 1, except that the molar ratio of nickel and cobalt ions was 1: 1.

<Electrode Preparation Example 4>

An electrode of an electrochemical device was manufactured in the same manner as in Preparation Example 1, except that the molar ratio of nickel and cobalt ions was 1: 2.

Electrode Preparation Example 5

An electrode of an electrochemical device was manufactured in the same manner as in Preparation Example 1, except that the molar ratio of nickel and cobalt ions was 1: 3.

Table 1 below is a table showing the measured values measured by applying the electrode prepared according to the electrode preparation examples 1 to 5 to the supercapacitor which is an electrochemical device.

At this time, the electrolyte used was a 1M KOH solution, and the reference electrode used Ag / AgCl. And the capacitance was measured at a scanning speed of 20 mV / s by the cyclic voltage-current method.

Ni: Co
(Molar ratio) Surface mass
(Mg / cm 2) Before authorization
Rye mill
Degree
(㎃ / ㎠) When charging
Liver (s) During discharge
Liver (s) Chung, Bang
Full efficiency
(%) Congratulation
Quantity (F / g) energy
Density (Wh
/ Kg) Power mill
Degrees (kW /
Kg) Electrification
Scholarly
Lee Yong Hyo
rate(%) electrode
Production Example 1 3: 1 328 One 69 59 85 453 13 47 17 electrode
Production Example 2 2: 1 213 One 187 151 80 1776 50 180 68 electrode
Preparation Example 3 1: 1 161 One 122 93 76 1453 41 147 55 electrode
Production Example 4 1: 2 113 One 51 41 80 911 26 94 35 electrode
Preparation Example 5 1: 3 196 One 41 37 90 474 13 14 18

Referring to Table 1, it can be seen that the electrodes of the electrochemical device having a molar ratio of nickel and cobalt in the range of 3: 1 to 1: 3 all have sufficient capacitance for use as the electrode of the supercapacitor. However, the electrode of the electrochemical device having a molar ratio of 3: 1 and 1: 3 of nickel and cobalt was 17% and 18%, respectively, and exhibited low characteristics in terms of utilization efficiency.

Therefore, when the electrode of the electrochemical device having a molar ratio of nickel and cobalt of 2: 1 to 1: 2 is applied to the super capacitor, it can be seen that the characteristics of the super capacitor are excellent.

3 is an electron microscope image of the electrode prepared according to the Preparation Example 2 at various magnifications.

Referring to FIG. 3, it can be seen that an electrode manufactured according to an embodiment of the present invention includes nanowires in an active layer.

4A to 4D are graphs of electrochemical characteristics of the supercapacitor to which the electrode manufactured according to Electrode Preparation Example 2 is applied. At this time, the electrolyte used was a 1M KOH solution, and the reference electrode used Ag / AgCl.

Referring to FIG. 4A, it can be seen that the supercapacitor to which the electrode manufactured according to the exemplary embodiment of the present invention is applied has a high redox peak as a result of the cyclic voltammetry measurement.

Referring to FIG. 4B, the supercapacitor to which the electrode manufactured according to the exemplary embodiment of the present invention is applied has a relatively symmetrical charge / discharge characteristic and has a long overall charge / discharge time. Since the amount of is similar to the excellent device stability, it can be seen that the capacitance (capactance) is high.

Referring to Figure 4c, it can be seen that the electrode produced in accordance with an embodiment of the present invention has a low resistance of 1 Ω / ㎠ in the electrode. Therefore, it can be seen that the electrode of the electrochemical device applied to the supercapacitor has a low internal resistance.

Referring to FIG. 4D, it can be seen that the supercapacitor to which the electrode manufactured according to the exemplary embodiment of the present invention is applied has a small change in capacitance due to repeated charging and discharging, thereby enabling stable charging and discharging.

Electrode Preparation Example 6

The activated carbon paste, which is well dispersed with a dispersant (Triton X), was evenly spread on a stainless steel substrate using a glass rod and heated to a temperature of 400 ° C. to remove impurities.

CoCl ₂ and Ni (NO ₃ ) ₂ · 6H ₂ O are used as precursors of cobalt and nickel, so that the molar ratio of nickel and cobalt ions is 1: 1 so that 0.1M CoCl ₂ and 0.1M Ni (NO ₃ ) ₂ 6H ₂ O was dissolved in an aqueous solution, and ammonia was added to prepare an aqueous solution of cobalt and nickel ions having a pH of 12.

The aqueous solution was impregnated with a stainless steel substrate which is a conductive current collector coated with activated carbon, coated at a temperature of 343 K for 1 hour to prepare cobalt-nickel hydroxide nanowires, and then dried to prepare an electrode of an electrochemical device. .

<Electrode Preparation Example 7>

An electrode of an electrochemical device was manufactured in the same manner as in Preparation Example 6, except that the active carbon was not coated between the current collector and the electrode active material.

Electrode Preparation Example 8

An electrode of an electrochemical device was manufactured in the same manner as in Preparation Example 6, except that the molar ratio of nickel and cobalt ions was 2: 1.

Table 2 below is a table showing measured values measured by applying the electrodes of the electrode preparation examples 6 to 8 to the supercapacitor which is an electrochemical device.

Ni: Co
(Molar ratio) Carbon film of current collector
Coating presence Charging time
(s) Discharge time
(s) Charge / discharge
efficiency(%) Storage capacity
(F / g) Energy density
(Wh / kg) Power density
(kW / kg) electrode
Preparation Example 6 1: 1 ○ 250 230 92 2500 420 1512 electrode
Preparation Example 7 1: 1 × 122 93 76 1453 41 147 electrode
Preparation Example 8 2: 1 × 187 151 80 1776 50 180

Referring to Table 2, the nickel-cobalt hydroxide electrode using the carbon film-coated current collector showed better performance than the electrode using the current collector without the carbon film in all aspects such as storage capacity, energy density, and power density.

Therefore, when the electrode of the electrochemical device manufactured by coating the carbon film on the current collector is applied to the super capacitor, it can be seen that the characteristics of the super capacitor can be further improved.

5A is an electron microscope image of an electrode manufactured according to the electrode preparation example 6 at various magnifications, and FIG. 5B is an electron microscope image of an electrode manufactured according to the electrode preparation example 7.

5A and 5B, it can be seen that the electrode manufactured according to the embodiment of the present invention includes nanowires in the active layer. In addition, in the case of nickel-cobalt nanowires manufactured after coating the carbon film on the current collector, the diameter of the nickel-cobalt nanowires produced without coating treatment is thinner and the number of wires is also higher. It can be seen that the nickel-cobalt hydroxide electrode has a higher surface area and thus is a cause of showing better performance.

6A to 6D are graphs of electrochemical characteristics of supercapacitors to which electrodes prepared according to embodiments of the present invention are applied.

6A is a cyclic voltage-current graph according to a scanning speed of a nickel-cobalt hydroxide electrode prepared using an active carbon-coated current collector according to Preparation Example 6, having a high redox peak and having 20 to 100 mV. In the range of / s, the redox curves are distinct.

6B shows (i) nickel-cobalt hydroxide electrode (Preparation Example 6) coated with activated carbon, (ii) nickel-cobalt hydroxide electrode (Preparation Example 7) uncoated with activated carbon, and (iii) only an activated carbon layer The cyclic current graph shows that the nickel-cobalt hydroxide electrode with the activated carbon layer shows a wider operating voltage range and circulating current curve than the electrode without. This indicates that nickel-cobalt hydroxide electrodes with an activated carbon layer have higher capacitance, energy density, and power density than those that do not.

6c is a charge / discharge graph of an activated carbon-coated nickel-cobalt electrode prepared according to Preparation Example 6 of the electrode. Since the symmetry is high, the amount of the electrode material participating in the charge and the electrode material participating in the discharge are similar. The long capacitance from overcharging to discharging shows a high capacitance.

FIG. 6D is an impedance graph of the electrode manufactured according to the Preparation Example 6, and it can be seen that it has a low internal resistance of 1Ω / cm ² .

Claims (18)

Current collector; And
An electrochemical device electrode comprising an active material layer containing a metal hydroxide nanowire with one end in the longitudinal direction toward the top of the current collector. The method of claim 1,
The metal hydroxide nanowires are N (OH) ₂ · mH ₂ O, M (OH) ₂ · mH ₂ O, and [N (OH) ₂ ] _1-x [M (OH) ₂ ] _x · mH ₂ O. It contains two kinds of metal hydroxides selected from the group consisting of, wherein N and M are different kinds of metals selected from the group consisting of Ca, Mg, Fe, Co, Ni, Cu and Zn, 0 <X <1 , m is 0 to 10 electrochemical device electrode. The method of claim 2,
N and M are each Ni and Co electrochemical device electrode. The method of claim 1,
Electrochemical device electrode further comprises a conductive carbon film interposed between the current collector and the active material layer. The method of claim 1,
The active material layer is an electrochemical device electrode further containing a conductive carbon material. The method according to claim 4 or 5,
The conductive carbon is at least one selected from the group consisting of carbon nanotubes, activated carbon, graphene and graphene oxide electrochemical device electrode. Current collector; And
On the current collector _{N (OH) 2 · mH 2} O, M (OH) 2 · mH consisting of ₂ O, and _{[N (OH) 2] 1} -x [M (OH) 2] x · mH 2 O It contains two kinds of metal hydroxides selected from the group, wherein N and M are different kinds of metals selected from the group consisting of Ca, Mg, Fe, Co, Ni, Cu and Zn, 0 <X <1, m is an electrochemical device electrode comprising an active material layer of 0 to 10. Preparing a metal precursor aqueous solution containing a first metal salt, a second metal salt having a metal different from the first metal salt, and a base material; And
Impregnating a current collector in the aqueous metal precursor solution to form a metal hydroxide nanowire with one end in the longitudinal direction toward the top of the current collector to form an electrochemical device electrode. 9. The method of claim 8,
The first metal salt is M (X) ₂ · mH ₂ O, the second metal salt is N (Y) ₂ · mH ₂ O, and N and M are Ca, Mg, Fe, Co, Ni, Cu, and Zn Selected from the group consisting of Other types of deulyigo metal, X and Y are independently selected, Cl ^-, NO ₃ ^- and CHOO ^- is selected from the group consisting of a, m is the method of manufacturing an electrochemical device electrodes 0-10. 9. The method of claim 8,
PH of the aqueous metal precursor solution in the step of forming the metal hydroxide nanowires is 7 to 14 manufacturing method of the electrochemical device electrode. 9. The method of claim 8,
Forming the metal hydroxide nanowires is a method of manufacturing an electrochemical device electrode performed at a temperature of 50 ℃ to 100 ℃. 9. The method of claim 8,
Forming the metal hydroxide nanowires is a method of manufacturing an electrochemical device electrode performed for 30 minutes to 3 hours. 9. The method of claim 8,
Before forming the metal hydroxide nanowires
The method of manufacturing an electrochemical device electrode, characterized in that it further comprises the step of forming a conductive carbon film on the current collector. 9. The method of claim 8,
The metal precursor aqueous solution further comprises a conductive carbon material. 9. The method of claim 8,
Before forming the metal hydroxide nanowires
Impregnating a current collector in the aqueous metal precursor solution, to form a metal hydroxide nucleus on the current collector further comprising the manufacturing method of the electrochemical device electrode. 16. The method of claim 15,
Forming a metal hydroxide nucleus on the current collector
And removing the current collector impregnated in the aqueous metal precursor solution and drying the electrode. A first metal salt of M (X) ₂ · mH ₂ O, a second metal salt of N (Y) ₂ · nH ₂ O, and a base material, wherein N and M are Ca, Mg, Fe, Co, Ni, deulyigo metal of different types selected from the group consisting of Cu and Zn, X and Y are independently selected, Cl ^-, nO ₃ ^- and CHOO ^- is selected from the group consisting of a, m is the metal precursor solution from 0 to 10 Preparing a; And
Impregnating a current collector in the aqueous metal precursor solution to form an active material layer on the current collector. A first electrode including a current collector and a first active material layer on the current collector;
A second electrode including a current collector and a second active material layer on the current collector;
A separator interposed between the first electrode and the second electrode; And
It includes an electrolyte for ion exchange,
The first active material layer of the first electrode is an electrochemical device containing a metal hydroxide nanowire with one end in the longitudinal direction toward the top.

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