KR102618025B1 - Composite for supercapacitor electrode, supercapacitor using the same, and manufacturing method thereof - Google Patents

Abstract

The composite material for supercapacitor electrodes according to the present invention includes an amine-based compound; conductive polymer; graphene oxide; and a metal oxide, wherein the amine compound, conductive polymer, and graphene oxide form a matrix, and the metal of the metal oxide forms a chelate with the matrix.

Description

Composites for supercapacitor electrodes, supercapacitors containing the same, and manufacturing method thereof {COMPOSITE FOR SUPERCAPACITOR ELECTRODE, SUPERCAPACITOR USING THE SAME, AND MANUFACTURING METHOD THEREOF}

The present invention relates to a composite material for supercapacitor electrodes, a supercapacitor containing the same, and a method of manufacturing the same. More specifically, the present invention relates to a composite material for supercapacitor electrodes that can increase charge/discharge performance and improve energy storage ability with a self-charging function, a flexible supercapacitor using the same, and a method of manufacturing the same.

In general, a supercapacitor is a high-output electrical energy storage device that quickly stores electrical energy and supplies high current instantaneously or continuously.

With the recent emergence of smart wearable electronic devices, demand for small-sized energy storage devices is increasing. Smart wearable electronics are evolving from non-conformal smart devices that are stiff, bulky, low-performance, and high-maintenance to flexible devices that can reliably mimic and adapt to the human body.

Smart wearable electronic devices are complex systems in which various components with different functions make up the device, including power supply units, display settings, multiple sensor arrays, and transistor arrangements. At this time, maintaining the charge and discharge of the power supply unit is a major problem that prevents the widespread application of wearable electronic devices, and the development of an energy source that supplies adequate power during long-term use is necessary.

In the case of lithium-ion batteries, they have the advantage of high energy density because they can store energy by charging and discharging power for a long time through chemical reactions, but they are bulky and have a structure that makes it difficult to provide flexibility, so they are widely applied to wearable electronic devices. It's difficult to do.

Meanwhile, thin-film supercapacitors require flexibility because they can be easily damaged in flexible environments, and there is a need to increase the capacity of supercapacitors by utilizing various electrolyte sources such as solar energy, kinetic energy, air, and sweat.

Therefore, it has flexibility by minimizing the structure and arrangement that can be destroyed, and can self-charge using electrolyte, increasing charging and discharging performance. It can also be used as an energy storage device for various smart wearable electronic devices by increasing the energy storage ability of the electrolyte. There is an urgent need to develop composite materials for supercapacitor electrodes and supercapacitors using them.

As background technology for the present invention, an electric double layer capacitor is disclosed in Korean Patent Publication No. 10-2005-0113632.

The purpose of the present invention is to provide a composite material for supercapacitor electrodes that is capable of self-charging using a dual electrolyte containing sweat, thereby increasing charge/discharge performance and energy storage capacity.

Another object of the present invention is to provide a supercapacitor containing a composite material and a method for manufacturing the same.

The above and other objects of the present invention can all be achieved by the present invention described below.

1. One aspect of the present invention relates to composite materials for supercapacitor electrodes.

The composite material for supercapacitor electrodes includes an amine-based compound; conductive polymer; graphene oxide; and a metal oxide, wherein the amine compound, conductive polymer, and graphene oxide form a matrix, and the metal of the metal oxide forms a chelate with the matrix.

2. In the first embodiment, the amine compound includes tris(2-aminoethyl)amine, and the conductive polymer is 3,4-ethylenedioxythiophene (3,4). -ethylenedioxythiophene), and the metal oxide may include copper oxide (CuO).

3. In the first or second embodiment, a cavity may be formed in the composite material for supercapacitor electrodes.

4. In any one of embodiments 1 to 3 above, the composite material for supercapacitor electrodes may have a strain rate of 12% or more and a tensile strength of 22 MPa or more.

5. Another aspect of the present invention relates to a self-charging supercapacitor using a dual electrolyte. The supercapacitor includes a current collector; At least one electrode stacked on the current collector; Electrolyte imprinted on the electrode; and a metal wire provided on an upper portion of the electrode, wherein the electrode is formed from the composite material.

6. In the above 5 embodiments, the composite material includes tris(2-aminoethyl)amine, 3,4-ethylenedioxythiophene, graphene oxide, and oxidation. It contains copper (CuO), and the copper can form a chelate.

7. In embodiment 5 or 6 above, the current collector may include fabric or ITO/PET.

8. In any one of embodiments 5 to 7 above, the electrolyte includes an ionic liquid, and may be mixed with sweat discharged from the human body.

9. In any one of embodiments 5 to 8 above, the area capacitance of the supercapacitor may be 36 F·cm ^-2 at 0.2 mA·cm ^-2 .

10. In any one of the embodiments 5 to 9 above, the supercapacitor can preserve more than 90% of the initial capacitance after 200 bending tests at bending radii of 7.0 mm and 3.5 mm.

11. In any one of the embodiments 5 to 10 above, the supercapacitor may have a CV profile voltage increased to 3.5 V according to a cyclic current voltage measurement under a dual electrolyte condition containing ionic liquid and sweat.

12. In any one of the embodiments 5 to 11 above, the supercapacitor may be capable of self-charging under electrolyte conditions using ionic liquid, sweat, or a combination thereof.

13. Another aspect of the present invention provides a smart wearable electronic device including the supercapacitor as a power unit.

14. Another aspect of the present invention relates to a method of manufacturing a self-charging supercapacitor using a dual electrolyte.

The supercapacitor manufacturing method includes (a) hydrothermal synthesis of a metal oxide precursor and hydrazine to prepare a dispersion containing a metal oxide;

(b) adding graphene oxide and the dispersion to a solution containing a conductive polymer, adding an ionic liquid as a catalyst and stirring to prepare a composite composition;

(c) drying the composite composition to obtain a composite film;

(d) attaching the composite film to a current collector.

15. In the 14th embodiment above, the ionic liquid may be 1-Butyl-3-methylimidazolium tetrafluoroborate.

The composite material for supercapacitor electrodes according to the present invention has high mechanical properties and can be used as a film-type electrode, and the supercapacitor containing it is self-sustaining by a double electrolyte through ionic liquid and sweat emitted from the human skin. Charging occurs, and as an energy storage device, the charging and discharging performance of the supercapacitor can be increased and the energy storage ability can be dramatically improved.

In addition, the method of manufacturing a self-charging supercapacitor using a dual electrolyte gives flexibility to the supercapacitor, so it can be used as a power supply unit for smart wearable electronic devices, and physical properties such as tensile strength can be improved.

A smart wearable electronic device including a supercapacitor according to another aspect of the present invention can be designed freely with reduced form constraints.

Figure 1 is a schematic diagram of a self-charging supercapacitor using a dual electrolyte according to an embodiment of the present invention.
Figure 2 is a photograph of a thin-film supercapacitor with copper wire installed on the ITO-PET substrate according to Figure 1.
Figure 3 is a schematic diagram showing the operation process of a self-charging supercapacitor using a dual electrolyte according to an embodiment of the present invention.
Figure 4 is a schematic diagram showing the movement of charge due to redox reaction in the ionic liquid mode and the mixed mode of ionic liquid and sweat in a self-charging supercapacitor using a dual electrolyte according to an embodiment of the present invention.
Figure 5 is a process flow chart of a method for manufacturing a self-charging supercapacitor using a dual electrolyte according to another aspect of the present invention.
Figure 6 shows the process of forming a copper chelate by adding copper sulfate to a mixture of TREN, PEDOT, and GO in a composite material according to an embodiment of the present invention.
Figure 7 is a photograph of a gel-state composite film according to one embodiment of the present invention.
Figure 8 is a graph showing mechanical durability using UTM in a composite material according to an embodiment of the present invention.
Figure 9 is an X-ray diffraction analysis graph of a composite material according to one embodiment of the present invention.
Figure 10 is an X-ray spectroscopic analysis graph of a composite material according to one embodiment of the present invention.
Figure 11 is an X-ray spectroscopic analysis graph for N _1s of a composite material according to one embodiment of the present invention.
Figure 12 is an X-ray spectroscopic analysis graph for O _1s of a composite material according to one embodiment of the present invention.
Figure 13 is a high-resolution X-ray spectroscopic analysis graph of Cu _2p of a composite material according to one embodiment of the present invention.
Figure 14 is an X-ray spectroscopic analysis graph for S _2p of a composite material according to one embodiment of the present invention.
Figure 15 is a scanning electron microscope photograph of a composite material according to one embodiment of the present invention.
Figure 16 is a scanning electron microscope photograph showing a cross section of a composite material according to one embodiment of the present invention.
Figure 17 is a high-resolution scanning electron microscope photograph of a composite material according to one embodiment of the present invention.
Figure 18 shows the CV curve by cyclic voltammetry of a supercapacitor using a film containing an amine-based compound and a conductive polymer, and a film in which graphene oxide is added to the amine-based compound and the conductive polymer as electrodes.
Figure 19 shows a CV curve according to the circulating voltage current of a supercapacitor including a composite material as an electrode according to an embodiment of the present invention.
Figure 20 is a graph showing the CV curve according to changing the scan rate from 10 mV/s to 250 mV/s in the cyclic voltage-current measurement of a supercapacitor containing a composite material as an electrode according to an embodiment of the present invention.
Figure 21 shows a Nyquist diagram according to electrical impedance spectroscopy (EIS) measurement after initial charge and discharge of a film containing graphene oxide added to an amine compound and a conductive polymer.
Figure 22 is a graph showing the charging and discharging results of a supercapacitor containing a composite material as an electrode according to an embodiment of the present invention by the constant current charging and discharging method at a low current density.
Figure 23 is a graph showing the charging and discharging results of a supercapacitor containing a composite material as an electrode according to an embodiment of the present invention by the constant current charging and discharging method at a high current density.
Figure 24 is a graph showing the CV curve according to cyclic voltage-current measurement when sweat is included in the electrolyte in a supercapacitor including a composite material as an electrode according to an embodiment of the present invention.
Figure 25 is a graph showing the results of electrochemical impedance spectroscopy (EIS) measurement when sweat is included in the electrolyte in a supercapacitor containing a composite material as an electrode according to an embodiment of the present invention.
Figure 26 is a graph showing the results of galvanostatic charge/discharge (GCD) measurement when sweat is included in the electrolyte in a supercapacitor including a composite material as an electrode according to an embodiment of the present invention.
Figure 27 shows the molecular structure of graphene oxide substituted with various functional groups.
Figure 28 is a photograph of a flexibility test of a supercapacitor including a composite material as an electrode on an ITO/PET substrate according to an embodiment of the present invention.
Figure 29 is a graph showing the CV profile before and after measuring the flexibility of a supercapacitor including a composite material as an electrode on an ITO/PET substrate according to an embodiment of the present invention.
Figure 30 is a graph showing the results of electrochemical impedance spectroscopy (EIS) measurement before and after measuring the flexibility of a supercapacitor containing a composite material as an electrode on an ITO/PET substrate according to an embodiment of the present invention.
Figure 31 is a graph showing the energy storage performance of a supercapacitor including a composite material as an electrode on an ITO/PET substrate according to an embodiment of the present invention before and after measuring the flexibility.
Figure 32 is a photograph of a flexibility test of a supercapacitor including a composite material as an electrode on a fabric substrate according to an embodiment of the present invention.
Figure 33 is a graph showing the CV profile before and after measuring the flexibility of a supercapacitor including a composite material as an electrode on a fabric substrate according to an embodiment of the present invention.
Figure 34 is a graph showing the results of electrochemical impedance spectroscopy (EIS) measurement before and after measuring the flexibility of a supercapacitor including a composite material as an electrode on a fabric substrate according to an embodiment of the present invention.
Figure 35 is a graph showing the energy storage performance of a supercapacitor including a composite material as an electrode on a fabric substrate according to an embodiment of the present invention before and after measuring the flexibility.
Figure 36 is a photograph of a supercapacitor including a composite material as an electrode according to an embodiment of the present invention being worn on the human body and allowing sweat discharged into the electrolyte.
Figure 37 is a photo of a mini-fan operating a supercapacitor including ITO/PET and a composite material on a fabric substrate as electrodes in one embodiment of the present invention.
Figure 38 is a photograph of the LED operation of a supercapacitor including ITO/PET and a composite material on a fabric substrate as electrodes in one embodiment of the present invention.
Figure 39 is a photograph of a thermohygrometer operating a supercapacitor including ITO/PET and a composite material on a fabric substrate as electrodes in one embodiment of the present invention.
Figure 40 is a graph showing the change in CV curve over sweat wetting time of a supercapacitor including a composite material as an electrode according to an embodiment of the present invention.
Figure 41 is a graph showing the change in electrochemical impedance spectroscopy (EIS) measurement results over sweat wetting time of a supercapacitor containing a composite material as an electrode according to an embodiment of the present invention.
Figure 42 is a graph showing the change in the DCR value of the discharge current over sweat wetting time of a supercapacitor including a composite material as an electrode according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the attached drawings. However, the following drawings are provided only to aid understanding of the present invention, and the present invention is not limited by the following drawings. In addition, the shape, size, ratio, angle, number, etc. disclosed in the drawings are illustrative and the present invention is not limited to the matters shown.

Like reference numerals refer to like elements throughout the specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

When the positional relationship between two parts is described as ‘on’, ‘at the top’, ‘at the bottom’, ‘next to’, etc., unless ‘immediately’ or ‘directly’ is used, there is no difference between the two parts. One or more different parts may be located.

Positional relationships such as 'upper', 'top', 'lower', 'lower', etc. are only written based on the drawings, and do not represent absolute positional relationships. In other words, depending on the observation position, the positions of 'top' and 'bottom' or 'top' and 'bottom' may change.

The present invention will be described in detail below.

Since the use of thin-film supercapacitors as energy storage devices is limited due to performance degradation issues, the present inventors used sweat as an electrolyte in an ionic liquid and a non-enzymatic path to complete a self-charging supercapacitor using a dual electrolyte that exhibits high performance. did.

One aspect of the present invention relates to a composite material for self-charging supercapacitor electrodes with dual electrolytes.

The composite material for electrodes includes an amine-based compound; conductive polymer; graphene oxide; and a metal oxide, wherein the amine compound, conductive polymer, and graphene oxide (hereinafter referred to as 'GO') form a matrix, and the metal of the metal oxide forms a chelate with the matrix.

Specifically, the amine-based compound is tri(2-aminoethyl)amine [Tris(2-aminoethyl)amine; Hereinafter ‘TREN’] may be included.

The conductive polymer is 3,4-ethylenedioxythiophene [(3,4-ethylenedioxythiophene); It may include 'EDOT'], and for example, it may be polymerized to form poly(3,4-ethylenedioxythiophene; hereinafter 'PEDOT').

The PEDOT is polymerized using an ionic liquid as a catalyst to form segments, and can react with GO and TREN to form a polysulfonate-amine derived polymer.

The metal oxide includes copper oxide (CuO).

The TREN and PEDOT form a matrix through a plurality of hydrogen bonds and can be combined with each other by reacting with the copper oxide chelate.

The GO may contain a carboxyl group, a hydroxyl group, and an epoxy group, and interacts with PEDOT combined with the TREN to form a matrix and allow the composite material to be manufactured in the form of a film.

Specifically, the reactive group of PEDOT can form a chelate by interacting with GO and copper of copper oxide.

The TREN, PEDOT, GO, and copper oxide can form a composite material according to Schemes 1 and 2 below.

[Scheme 1]

[Scheme 2]

Referring to _Schemes 1 and 2 above, EDOT, By polymerizing GO and TREN and adding copper oxide, a composite material in which copper oxide is chelated can be manufactured in the form of a film.

In one embodiment, the composite material for supercapacitor electrodes may have a cavity formed.

The composite may be limited by metal bonding and interaction with PEDOT on the surface of GO, forming cavities, increasing the specific surface area, and the surface may be rough and have a film-like form.

In one embodiment, the composite material for supercapacitor electrodes may have a strain rate of 12% or more and a tensile strength of 22 MPa or more.

The composite material can be manufactured in a film form to increase mechanical properties.

Specifically, because the composite film is formed by combining TREN, PEDOT, and GO-CuO chelate, mechanical properties can be improved.

If the composite film has physical properties within the above range, it can be used as an electrode for a supercapacitor to provide flexibility to the supercapacitor and effectively increase mechanical properties.

Another aspect of the present invention relates to a self-charging supercapacitor using a dual electrolyte.

Figure 1 is a schematic diagram of a self-charging supercapacitor using a dual electrolyte according to an embodiment of the present invention, and Figure 2 is a photograph of a thin-film supercapacitor with a copper wire installed on an ITO-PET substrate according to Figure 1.

Referring to Figures 1 and 2, the supercapacitor 1000 includes a current collector 100, an electrode 200, an electrolyte 300, and a metal wire 400.

The supercapacitor 1000 is a planar supercapacitor rather than a vertical type, and the current collector 100, electrode 200, electrolyte 300, and metal wire 400 can be placed together on a plane. there is.

The current collector 100 provides a space where the electrode 200 and the electrolyte 300 can be placed.

The current collector 100 may be a fabric or an ITO/PET film substrate 100.

When the current collector 100 is the fabric or ITO/PET substrate, flexibility can be provided to the supercapacitor 1000, and it has electrical conductivity to transfer electrons so that an electrochemical reaction occurs in the electrode 200. And, it can provide a path for electrons to move.

When the current collector 100 is an ITO/PET substrate, very fast and stable electron movement is possible and rapid charging and discharging are possible due to the metal oxide (ITO) coating.

When the current collector 100 is a fabric, the charging/discharging interval is stably increased in the dual electrolyte functionalization according to the absorption of sweat, enabling long-time charging and discharging.

The electrode 200 is formed on the current collector 100 and can form one electrode cell 200, and at least one electrode 200 is disposed on the substrate 100 to form a plurality of A supercapacitor (1000) equipped with an electrode cell can be constructed.

Since the electrode 200 is provided with one or more, power can be supplied independently even if some of the electrodes 200 are damaged, it is very suitable as a supercapacitor 1000 for wearable electronic devices.

The electrode 200 includes the composite material.

Specifically, the composite includes tris(2-aminoethyl)amine, 3,4-ethylenedioxythiophene, graphene oxide, and copper oxide (CuO). And, the copper may form a chelate.

Since the description of the composite material is repetitive, it will be omitted.

The electrolyte 300 is imprinted on the electrode 200.

Here, imprinting means that the electrolyte 300 is complexed with the electrode 200, and indicates that the electrolyte 300 exists in a separate phase from the electrode.

Specifically, the composite material has a cavity formed so that the electrolyte 300 can be composited with the electrode 200. Accordingly, the electrode 200 can include the electrolyte 300 within the composite material.

The electrolyte 300 may include an ionic liquid, for example, [BMIN]BF ₄ .

When the electrolyte 300 contains the [BMIN]BF ₄ , the electrode 200 can implement an ionic liquid mode, and charges can be moved and stored in the electrode 200.

In one embodiment, the electrolyte 300 is mixed with the [BMIN]BF ₄ and sweat, so that energy harvesting and storage capabilities can be increased through self-recharging by the double electrolyte.

Specifically, when the supercapacitor 1000 is attached to the surface of human skin and sweat is discharged from the human body, sweat can be injected into the electrolyte 300 to exhibit a self-recharging function by double electrolyte.

The metal wire 400 is provided on the electrode 200.

Specifically, the metal wire 400 is preferably a copper wire (Cu wire).

The metal wire 400 can increase the flow of current in the entire circuit including the supercapacitor 1000.

The area capacitance of the supercapacitor 1000 may be 36 F·cm ^-2 at 0.2 mA·cm ^-2 .

Specifically, the supercapacitor 1000 had a capacitance of up to 36 F·cm ^-2 in area capacitance evaluation according to a galvanic charge/discharge (hereinafter referred to as 'GCD') experiment based on the dual electrolyte 300. It can be increased and can exhibit increased capacitance compared to the single electrolyte 300.

In one embodiment, the supercapacitor 1000 can preserve more than 90% of the initial capacitance after 200 bending tests at bending radii of 7.0 mm and 3.5 mm.

The current collector 100 has flexibility, and since the electrode 200 is provided with flexibility by including the composite material, the supercapacitor 1000 also has flexibility, and mechanical properties can be increased to increase tensile strength. .

For example, since the capacitance can be preserved even at bending radii of 7.0 mm and 3.5 mm, the energy storage ability is groundbreaking by preserving more than 90% of the capacitance compared to the initial capacitance after 200 cycles of bending tests. can be improved.

The supercapacitor 1000 can increase the CV profile voltage to 3.5 V according to the cyclic current voltage measurement under dual electrolyte functionalization conditions containing ionic liquid and sweat.

The supercapacitor 1000 can accelerate the redox reaction by allowing sweat to flow into the electrolyte 300 and increase both charge capacity and capacitance, and the voltage according to the circulating current voltage measurement increases to 3.5 V, making it a smart wearable. It is very suitable as a power unit for electronic devices.

The operation of the supercapacitor 1000 is described as follows.

Figure 3 is a schematic diagram showing the operation process of a self-charging supercapacitor using a dual electrolyte according to an embodiment of the present invention, and Figure 4 is a schematic diagram showing the self-charging supercapacitor (1000) using a dual electrolyte according to an embodiment of the present invention. This is a schematic diagram showing the movement of charge according to the redox reaction in the ionic liquid mode and the dual electrolyte mode where ionic liquid and sweat are mixed.

Referring to Figures 3 and 4, PEDOT and TREN are combined by [BMIN]BF ₄ to form an intermediate, and when GO and CuO are added, a composite material (PEDOT/TREN/GO-CuO chelate) is formed.

[BMIN]BF ₄ may be imprinted on the composite to form an ionic liquid mode.

When the composite material is placed on the current collector 100 and the current collector 100 is flexible and attached to the skin of the human body, sweat discharged from the human body flows into the composite material and electrolyte (300) together with the ionic liquid. ) can form a dual electrolyte mode (sweat@ionic liquid mode).

The movement of charge due to oxidation and reduction occurs in the electrode, and electrons move from one electrode to operate an electric device connected to the outside of the supercapacitor 1000.

When the electrolyte 300 is composed of only ionic liquid in the supercapacitor 1000, it is difficult to secure sufficient capacitance, but when sweat is added to the electrolyte 300, the sodium ions (Na ⁺ ) contained in the sweat are By accelerating the oxidation-reduction reaction (Redox) of the ionic liquid, not only can the amount of charge transfer be increased, but also the capacitance of the supercapacitor 1000 can be effectively increased.

The supercapacitor (1000) has a thin film structure, but does not have a decrease in capacitance, uses sweat as the electrolyte (300), and is capable of self-charging by using sweat as the electrolyte (300) in a non-enzymatic route, providing excellent energy. Harvesting and storage systems can be provided.

The supercapacitor (1000) exhibits a maximum capacitance per surface area of 3600 mF·cm ^-2 in the dual electrolyte (300) mode, and an energy density of 450 mWh·cm ^-2 , which is 100 times higher than that of the supercapacitors known so far. can indicate.

The supercapacitor 1000 is capable of self-charging under electrolyte conditions using ionic liquid, sweat, or a combination thereof.

The supercapacitor 1000 can effectively produce electrical energy through an electrochemical reaction caused by sweat, and can produce and store electrical energy at the same time.

Another aspect of the present invention relates to a smart wearable electronic device including the supercapacitor 1000.

Since the supercapacitor 1000 is capable of self-charging, has flexibility, and is capable of excellent energy harvesting and storage, it can be used as a power unit for smart wearable electronic devices.

For example, the supercapacitor 1000 can be used as a power unit of a smart watch that is in direct contact with the wearer's skin, thereby dramatically increasing the operating period of the smart wearable electronic device.

Another aspect of the present invention relates to a method for manufacturing a self-charging supercapacitor using a dual electrolyte.

Figure 5 is a process flow chart of a method for manufacturing a self-charging supercapacitor using a dual electrolyte according to another aspect of the present invention.

Referring to FIG. 5, the method for manufacturing the supercapacitor includes the steps of (a) hydrothermally synthesizing a metal oxide precursor and hydrazine to prepare a dispersion containing a metal oxide;

(b) adding graphene oxide and the dispersion to a solution containing a conductive polymer, adding an ionic liquid as a catalyst and stirring to prepare a composite composition;

(c) drying the composite composition to obtain a composite film;

(d) attaching the composite film to a current collector.

First, a dispersion containing a metal oxide is prepared by hydrothermal synthesis of a metal oxide precursor and hydrazine (S100).

Specifically, the metal oxide precursor is copper sulfide (CuSO _4.· 5H ₂ O), and can be prepared by hydrothermal synthesis while mixing and stirring with hydrazine (N ₂ H ₄ ).

Graphene oxide and the dispersion are added to a solution containing a conductive polymer, and an ionic liquid is added as a catalyst and stirred to prepare a composite composition (S200).

Specifically, the conductive polymer may be PEDOT, the amine-based compound may be TREN, and the ionic liquid may be [BMIN]BF ₄ .

[BMIN]BF ₄ can be added to combine PEDOT and TREN with GO.

A composite film can be obtained by drying the composite composition (S300).

Specifically, it is preferable to cast the composite composition on a glass plate and dry it at 50 to 70°C.

The composite film is attached to the current collector (S400).

The prepared composite film is attached to a fabric or ITO/PET substrate to manufacture a thin-film supercapacitor.

The composite film constitutes an electrode and may be arranged in plural pieces. When the composite film constitutes an electrode, a metal wire may be placed on top of the electrode.

Finally, an electrode containing a composite material is placed on a substrate that is a current collector, and a supercapacitor with a copper wire on the electrode is recovered.

Hereinafter, the present invention will be described in more detail through examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example 1. Supercapacitor manufacturing

(1) Material preparation

Tris(2-aminoethyl)amine; TREN], 3,4-ethylenedioxythiophene, copper sulfide (CuSO ₄ .5H ₂ O), hydrazine (N ₂ H ₄ ), ionic liquid: 1-butyl-3-methyl Imidazolium tetrafluoroborate [1-butyl-3-methyl imidazolium tetrafluoroborate; BMIMBF ₄ ), and ammonium persulfate [(NH ₄ ) ₂ S ₂ O ₈ ] were purchased from Sigma Aldrich.

(2) Preparation of copper oxide

Copper oxide powder was prepared by hydrothermal synthesis of copper oxide precursor copper sulfide (CuSO ₄ ·5H ₂ O) and hydrazine (N ₂ H-) and stirring.

The obtained powder was centrifuged, washed 10 times in deionized water, washed 3 times with ethanol, and then dried in an oven to prepare a chelate.

(3) Composite manufacturing

First, EDOT (0.1M) was treated with [BMIM][BF ₄ ] ionic liquid and stirred for 2 hours. A mixture was prepared by slowly adding TREN and GO step by step to a dispersion containing copper oxide. The mixture was stirred for another hour and placed in a chemical bath at 80° C. for 12 hours to form a gel.

The obtained gel was cast on a glass plate and dried at 60°C. Afterwards, the physical properties of the obtained film were evaluated separately and used to manufacture thin-film supercapacitor electrodes.

(4) Manufacturing of dual electrolyte functional supercapacitor

Fabric as the current collector and ITO/PET were selected as the substrate, and the gel-like composite material was attached.

At this time, six electrode cells were arranged on a flat surface at regular intervals, and copper wire was placed on the top of the electrode and dried to complete the supercapacitor.

Electrodes were prepared on ITO-coated PET surfaces and knitted cotton fabrics, and a stable supercapacitor was designed in a symmetrical planar configuration.

The electrode area of the supercapacitor was maintained at 1.0 × 1.0 cm, and copper wire was used for planar array measurements and multiple settings of each electrode cell.

The supercapacitors arranged in a plane were attached to the skin of the human arm and sweat-soaked cloth using scotch tape for initial fixation.

Afterwards, the supercapacitor was treated in a sweat-soaked state to measure the performance of the supercapacitor according to the dual electrolyte, and its flexibility and repeated charging and discharging ability were evaluated.

Experimental Example 1. Composite mechanical strength

Figure 6 shows the process of forming a copper chelate by adding copper sulfate to a mixture of TREN, PEDOT, and GO in a composite according to an embodiment of the present invention, and Figure 7 shows a gel-state composite film according to an embodiment of the present invention. It's a photo of

Referring to Figures 6 and 7, it was confirmed that the composite material was applied in a chemical bath after polymerization to form a gel-like film, which can be used as an electrode that can be attached to a substrate.

Figure 8 is a graph showing mechanical durability using UTM in a composite material according to an embodiment of the present invention.

Referring to Figure 8, the mechanical durability of the manufactured composite (TREN/PEDOT/GO-CuO chelate) was measured using a UTM strength meter, and in order to compare the durability of the composite, a film combining only TREN and PEDOT (TREN/PEDOT) was used. ) and a film in which TREN and PEDOT were combined and GO was added (TREN/PEDOT/GO) were prepared respectively and their durability was compared.

High mechanical strength is essential for film-type electrodes in flexible supercapacitors, and sufficient tensile strength can also provide excellent durability and long service life of the electrode.

TREN/PEDOT film showed a tensile strength of 7.8 MPa at a strain rate of 9.1%, and TREN/PEDOT/GO film showed only a slight improvement in tensile strength.

On the other hand, the composite material (TREN/PEDOT/GO-CuO chelate) showed high tensile strength, which was due to the greatly increased interlayer interaction of the composite material, which resulted in the interaction between the TREN/PEDOT/GO polymer composite formed of highly oriented polymer chains and copper. This is due to sufficient hydrogen bonding.

It was confirmed that the manufactured composite (TREN/PEDOT/GO-CuO chelate) can be used as a film-type electrode.

Experimental Example 2. Confirmation of composite composition and crystal structure

Figure 9 is an X-ray diffraction analysis graph of a composite material according to one embodiment of the present invention.

Referring to FIG. 9, the TREN/PEDOT The diffraction peaks of GO overlapped around the 2θ angle of 9.8°, which was confirmed to represent the typical diffraction peak of polymer composites observed at 25.6°.

XRD analysis results for the composite (TREN/PEDOT/GO-CuO chelate) showed that peaks due to weak interaction at 2θ angles were observed at 10.3 ° and 25 °, which indicates the coordination of the copper chelate and the TREN/PEDOT/GO polymer composite. It represents.

The remaining sharp diffraction peaks, especially 2θ = 32.1°, 35.3°, 38.7°, and 52.7°, corresponded to the peaks at (110), (111), (200), and (202) (JCPDS NO.89-2529). , which showed a well-crystallized black copper mineral structure (tenorite).

As a result of XRD analysis, it was confirmed that a GO and polymer composite impregnated with copper chelate existed.

Figure 10 is an X-ray spectroscopic analysis graph of a composite material according to an embodiment of the present invention, Figure ₁₁ is an Figure 13 is an X-ray spectroscopic analysis graph for O _1s of a composite material according to one embodiment of the present invention, Figure 13 is a high _- resolution This is an X-ray spectroscopic analysis graph for S _2p of a composite material according to an embodiment.

Referring to Figures 10 to 14, XRD showed the main composition peaks of Cu _2p , O _1s , N _1s , C _1s , and S _2p .

The C _1s peak of the composite (TREN/PEDOT/GO-CuO chelate) showed CC and C=N at about 285 eV, and the S _2p peak of the TREN/PEDOT polymer appeared at 397 eV and 165 eV, respectively. Moreover, the satellite peak of copper observed at about 935 eV helps confirm the structure of the composite film.

The N _1s XPS scan showed three typical peaks at 398.5, 398.1, and 400.1 eV corresponding to the amine derivatives of TREN and PEDOT, respectively. Amines can improve the conductivity of polymer chains through electron delocalization.

The O _1s peak in the Confirmed.

Checking _the high _- resolution Cu _2p The dominant peaks at 938.1 and 954.7 eV correspond to the Cu _2p3/2 peaks of Cu ₊ and Cu ²⁺ species.

In Figure 14, peaks corresponding to Cu _2p1/2 were confirmed at 952.3 and 954.3 eV, which were confirmed to represent typical Cu ⁺ and Cu ²⁺ . The XPS spectrum of S _2p showed several possible peaks, for example, two typical S _2p signal bands observed between 160.7 and 163.2 eV, and these peaks were confirmed to be assigned to the sulfur atom of PEDOT.

Experimental Example 3. Composite surface analysis

Figure 15 is a scanning electron microscope photograph of a composite material according to an embodiment of the present invention, Figure 16 is a scanning electron microscope photograph showing a side cross-section of a composite material according to an embodiment of the present invention, and Figure 17 is an embodiment of the present invention. This is a high-resolution scanning electron microscope photo of a composite material according to an example.

Referring to Figure 15, it was confirmed that the composite had a very rough surface, which was confirmed to be because the film-like morphology was hindered by the polymer-metal linkage (CuO) interaction on the surface of GO.

Checking the SEM image of the TREN/PEDOT film, it was compared to a film with a very smooth surface, and no depressions corresponding to sulfur, nitrogen, oxygen, and carbon in the TREN/PEDOT film were identified.

In Figure 16, when checking the cross-section of the composite, it was confirmed that a cavity was formed, increasing the specific surface area, and a thickly filled network formed a film, but it was not in the form of a film.

The high-magnification SEM image in Figure 17 clearly showed that GO, TREN/PEDOT, and copper were distributed very homogeneously in the composite.

The obtained film-like morphology is due to the increase in polymer friction along the barrel wall due to the interaction of copper and GO. It appears that the dispersion tendency of the particles increases when stimulated by the ionic liquid environment, and the ionic liquid droplets connect each individual within the composite film and allow more control of parts.

As a result of EDX analysis of the composite, it was confirmed that the main constituent elements of C, O, N, S, and Cu were present in the composite, which supported that the composite was well formed and showed that it permeated homogeneously through the polymer network.

The observed copper layer provided visibility of the finished composite and revealed abundant reactive sites for chelating reactions.

Experimental Example 4. Supercapacitor electrochemical performance evaluation

The electrochemical performance of the supercapacitor containing the composite material according to Example 1 was evaluated.

Figure 18 shows the CV curve by the cyclic current-voltage method of a supercapacitor using a film containing an amine-based compound and a conductive polymer and a film containing graphene oxide added to the amine-based compound and a conductive polymer as an electrode, and Figure 19 shows the CV curve according to the circulating current voltage of a supercapacitor containing a composite material as an electrode according to an embodiment of the present invention, and Figure 20 shows a circulation curve of a supercapacitor including a composite material as an electrode according to an embodiment of the present invention. This is a graph showing the CV curve according to changing the scan rate from 10 mV/s to 250 mV/s in current voltage measurement.

Referring to Figures 18 to 20, a distinct increase in the CV area in the graph appeared after TREN/PEDOT was changed to graphene oxide, and it was also confirmed that it was changed to CuO.

The composite (TREN/PEDOT/GO-CuO chelate) increased the pseudocapacitance of the polymer-metal composite and the electric double layer capacitance (EDLC) of GO with respect to the total capacitance of the supercapacitor.

It was confirmed that the CV curve of the composite material showed superior performance than TREN/PEDOT and TREN/PEDOT/GO films.

Referring to FIG. 20, it was confirmed that when the scan rate was rapidly increased from 10 mV/s to 250 mV/s, a significant change in capacitance was observed and an increased CV area was observed.

Electrical impedance spectroscopy was measured to confirm the electrochemical performance of the supercapacitor.

Figure 21 shows a Nyquist diagram according to electrical impedance spectroscopy (hereinafter 'EIS') measurement after initial charge and discharge of a film containing graphene oxide added to an amine-based compound and a conductive polymer.

Referring to Figure 21, the vertical line in the high frequency region represents the distinct resistance of the copper chelate-based supercapacitor, indicating that performance can be maintained constant even after charging and discharging. The obtained EIS values were also analyzed using the “Zview” program.

Bulk resistance (R _s ) was measured to confirm the change in resistance due to the integration of the electrode, electrolyte, and current collector, and the R _ct area represented the resistance due to electron movement in the electrode and electrolyte. The effect of capacitance was evaluated from the double layer capacitance (C _dl ) along with the R _ct area. Wr is a Warburg element that can reveal changes in ion diffusion.

The supercapacitor containing the composite material according to the example as an electrode had an initial bulk resistance of 1.012 Ω·cm ² and showed 1.270 Ω·cm ² after a charge and discharge cycle. The R _ct value reached was 0.601 Ω·cm ² at the initial EIS and 0.803 Ω·cm ² after the charge/discharge cycle.

Wr was 56.07 Ω·cm ² when first measured by electrochemical impedance spectroscopy (EIS), and 28.15 Ω·cm ² after the galvanostatic charge/discharge (GCD) measurement, which is due to the difference between the electrode, ionic liquid, and sweat during the continuous charging and discharging process. It represents ionic diffusion between the dual electrolytes.

These results indicate that the electron transfer resistance changes indicate electrochemical compatibility of the electrodes, indicating ionic diffusion on or within the surface of the composite film, resulting in high capacitance performance, and electrolytes from sweat and ionic liquids wet onto the composite surface. The relationship between ions according to degree was established.

Figure 22 is a graph showing the charging and discharging results of a supercapacitor containing a composite material as an electrode according to an embodiment of the present invention by the constant current charge and discharge method at a low current density, and Figure 23 is a graph showing the results of charging and discharging according to an embodiment of the present invention. This is a graph showing the charging and discharging results of a supercapacitor containing composite materials as electrodes using the constant current charging and discharging method at high current density.

Referring to Figures 22 and 23, GCD measurements were performed from low to high current densities, with low current densities ranging from 0.25 mA·cm ^-2 to 7.0 mA·cm ^-2 and 10 mA·cm ^-2 to 100 mA. · Measured with high current density performance up to cm ^-2 .

The performance of the supercapacitor based on the dual electrolyte function of ionic liquid and sweat showed triangular symmetry at both low and high current densities, with distinctions related to electrochemical reversibility and capacitance.

Transformation of the GCD curve against time indicates changes in oxidation and reduction.

The area capacitance and energy density of the supercapacitor including the composite material according to the example as an electrode were measured according to Equations 1 and 2 below.

[Equation 1]

[Equation 2]

Here, I is the discharge current (A), Δt is the discharge time (s), the applied potential window is ΔV, and A means the total area of the supercapacitor.

The area capacitance value determined for the supercapacitor was 36 F·cm ^-2 at 0.2 mA·cm ^-2 , and the energy density was 4.5 Wh·cm ^-2 under dual electrolyte functionalization conditions containing sweat and ionic liquid.

Here, the relationship between area capacitance and current density confirms that the area capacitance substantially decreases as the current density increases, and at low current densities, the electrolyte ions have sufficient time to proceed with the redox reaction in all areas of the composite. As the reaction progressed, it eventually decreased at high current density levels.

Meanwhile, the electrochemical performance of the supercapacitor by dual electrolyte functionalization was compared with that of the supercapacitor using TREN/PEDOT film and TREN/PEDOT/GO film as electrodes.

It was confirmed that a supercapacitor functionalized with a graphene oxide film can have a significantly increased dislocation potential compared to a supercapacitor containing a simple TREN/PEDOT film. The measured EIS was also confirmed to show good results for films mediated by graphene oxide.

Corresponding charge-discharge experiments were performed at various current densities from 0.25 mA·cm ^-2 to 7.0 mA·cm ^-2 , and the galvanostatic charge-discharge curves obtained for the two types of supercapacitors showed typical GCD at various current densities. shows a triangular symmetric curve.

The calculated areal capacitance is 0.24 F·cm ^-2 for the supercapacitor containing TREN/PEDOT film and 0.68 for the supercapacitor containing TREN/PEDOT/GO film under dual electrolyte functionalization conditions of sweat and ionic liquid. It was F·cm ^-2 .

Meanwhile, the efficiency of the dual electrolyte in the supercapacitor was compared with the ionic liquid electrolyte mode that does not use sweat as an electrolyte.

Figure 24 is a graph showing the CV curve according to the cyclic voltage current measurement when sweat is included in the electrolyte in a supercapacitor containing a composite material as an electrode according to an embodiment of the present invention, and Figure 25 is a graph showing the CV curve according to an embodiment of the present invention. It is a graph showing the results of electrochemical impedance spectroscopy (EIS) measurement when sweat is included in the electrolyte in a supercapacitor containing a composite material as an electrode, and Figure 26 is a graph showing the results of electrochemical impedance spectroscopy (EIS) measurement for a supercapacitor containing a composite material according to an embodiment of the present invention as an electrode. This graph shows the results of constant current charge/discharge (GCD) measurement when sweat is included in the electrolyte in a supercapacitor.

24 to 26, the CV curve measured in ionic liquid mode showed unique square redox pseudocapacitance properties. This performance is lower compared to sweat and dual electrolyte functionalization.

The calculated area capacitance was 15.2 F·cm ^-2 and the energy density was 2.15 Wh·cm ^-2 . The performance and measured CV profile of the supercapacitor using TREN/PEDOT film and TREN/PEDOT/GO film as electrodes under only ionic liquid conditions showed a representative redox profile in the CV graph, and the EIS results showed that the electrode and electrolyte system It was confirmed that equivalent resistance performance was achieved.

The results of the GCD experiment showed an almost square curve with notable performance under various changes in current density.

The area capacitance of each supercapacitor including TREN/PEDOT film and TREN/PEDOT/GO film as electrodes was 0.045 F·cm ^-2 and 0.33 F·cm ^-2 .

From this difference in performance, it was confirmed that the capacitance of the supercapacitor increased under the dual electrolyte functionalization condition.

Therefore, in the electrochemical experiment, the supercapacitor containing the composite material according to Example 1 as an electrode was compared to the supercapacitor simply containing TREN/PEDOT film and TREN/PEDOT/GO film as electrodes, respectively, ionic liquid and sweat. It was confirmed that a thin-film supercapacitor can exhibit excellent performance, especially under dual electrolyte function conditions using both as electrolytes.

These results also identify the interlayer spacing of the supercapacitor and support the movement of ions or ionic diffusion in solid and wet electrolyte conditions on the composite electrode surface.

Experimental Example 5. Confirmation of supercapacitor charging and discharging mechanism

The charging and discharging mechanism of the supercapacitor manufactured according to Example 1 was performed according to Schemes 1 and 2 below.

Here, the electron charging mechanism in the composite electrode material occurs through two reactions.

Ions in the electrolyte medium were adsorbed or desorbed on the surface of the electrode in the composite electrode according to Scheme 1 below.

[Scheme 1]

The second mechanism is that positive ions (C ⁺ ) are intercalated into a permeable electrode material according to Scheme 2 below.

[Scheme 2]

Here, C ⁺ is a cation derived from electrolytes (sweat and ionic liquid). Additionally, the high conductivity and internal cavities of the electrode surface can increase electrolyte circulation and accumulate increased active surface sites.

Additionally, considering the redox reactions in PEDOT, the sites of copper chelate and graphene oxide may play an important role in the energy harvesting and storage process.

The redox process and electron transfer mechanism within the composite are expressed in Scheme 3 below.

[Scheme 3]

The oxidation-reduction reaction of copper chelate is carried out according to Scheme 4 below.

[Scheme 4]

Here, a reaction occurred at the site of GO according to Scheme 5 below.

[Scheme 5]

Meanwhile, electrochemical charge storage in PEDOT is associated with surface doping and dedoping processes following the entry and exit of counterions from the polymer chain, which is closely related to electrical conductivity, ion diffusion, and surface area in electrodes containing PEDOT. .

Various attempts were made to improve the capacitance performance of the PEDOT electrode under dual electrolyte functionalization conditions including sweat and ionic liquid, and the electrocatalyst in PEDOT, a conductive polymer electrode, focused on the oxygen reduction reaction, which is electrochemical. It has become an important method of use in reactions.

Scheme 3 above involves reducing PEDOT to a neutral configuration, which can represent a transition state in which two electrons move, representing a dynamically favorable situation when sweat and ionic liquid react.

Moreover, PEDOT is a conducting polymer, possessing atoms that are abundant in nature, and its active electrocatalytic sites can promote specific preferred reaction pathways, making it suitable for the electrode system of supercapacitors. Additionally, the absence of an underlying shielding layer along the electrode-electrolyte interface allows for active interactions for charge transfer in the supercapacitor system. Because PEDOT polymer-electrolyte interactions distinguish conductive polymers in heterogeneous electrocatalysts, PEDOT-mediated composites can be reached by neutral and ionic reactants with mixed electron-ion conductors.

The high density of positive charge carriers inside the PEDOT phase is very important for electrical conductivity and allows the charge accumulation of negative ions to be taken into account, and these self-styled primary dopants are dispersed throughout the composite electrode, giving the supercapacitor electrode system high conductivity. made it possible to do so.

According to Scheme 4 above, the functional groups of TREN, PEDOT, and GO in the composite can easily interact with the negatively and positively charged active sites of the Cu-mediated chelate and induce the formation of zwitterions during the redox process.

Therefore, the excellent electrocatalytic activity of the composite (TREN/PEDOT/GO-CuO chelate) electrode can lead to an excellent electrochemical device with an excellent redox process.

Meanwhile, GO is functionalized with conductive polymers or metal oxides, allowing composite materials to maintain their conductive performance and increase redox reactions through their reactors.

Their initial electrochemical performance was investigated using CV. The redox peak according to the CV profile was similar to the electrochemical reaction occurring on the surface of the supercapacitor electrode.

The electrochemical profile observed in the CV and EIS curves of carbon-based composites can be defined as a redox reaction at a specific location without a complete explanation of the specific reaction proceeding at a specific site, and is a semi-reversible reaction according to Scheme 5 above. The redox reaction of the GO site was confirmed.

Additionally, the pseudocapacitance is related to the redox reaction of the quinoid and hyperquinoid groups of GO.

Figure 27 shows the molecular structure of graphene oxide substituted with various functional groups.

Referring to Figure 27, GO is generally a semi-aromatic network containing sp3/sp2-hybrid carbon atoms organized by bonding functional groups such as carboxyl, carbonyl, epoxyl, and hydroxyl, and hydroxyl groups and A large amount of epoxy groups was added to the composites due to their high activity in electrochemical processes and their ability to react with larger molecules to form covalent bonds, and functional groups such as alpha-diketones, hydroquinoids, and lactones were used to improve electrochemical properties of GO. It was confirmed that chemical improvement was possible.

Experimental Example 6. Confirmation of supercapacitor mechanical properties

According to the example, the mechanical properties of the completed supercapacitor were confirmed by arranging a copper wire connection line as a current collector and an electrode containing a composite material on an ITO/PET substrate.

Figure 28 is a photograph of a flexibility test of a supercapacitor including a composite material as an electrode on an ITO/PET substrate according to an embodiment of the present invention.

Referring to Figure 28, the mechanical flexibility of the manufactured supercapacitor was tested, and changes in physical appearance were confirmed. The supercapacitor was placed in a bending tester, and its performance was recorded and documented through a workstation.

Flexibility performance was measured in horizontal position, bending radii of 7.0 mm and 3.5 mm.

As a result of the mechanical flexibility test, it was confirmed that there was no change in appearance due to the bending test.

Figure 29 is a graph showing the CV profile before and after measuring the flexibility of a supercapacitor including a composite material as an electrode on an ITO/PET substrate according to an embodiment of the present invention, and Figure 30 is a graph showing the ITO/PET according to an embodiment of the present invention It is a graph showing the results of electrochemical impedance spectroscopy (EIS) measurement before and after measuring the flexibility of a supercapacitor containing a composite material as an electrode on a substrate, and Figure 31 is a graph showing the results of electrochemical impedance spectroscopy (EIS) measurement of a supercapacitor containing a composite material as an electrode according to an embodiment of the present invention. This is a graph showing the energy storage performance of the supercapacitor including before and after measuring the flexibility.

Referring to Figures 29 to 31, the CV profile before and after measuring mechanical flexibility showed very low current fluctuations, and it was confirmed that the change in current and voltage according to the bending test was not significant.

The EIS measurement results under different bending conditions also showed minimal differences, with weak fragmentation appearing at low frequencies only when the bending radius was 3.5 mm.

Energy storage performance was evaluated after 1000 cycles of bending tests, and it was confirmed that the supercapacitor device was able to preserve 98% of its initial capacitance even after 200 bending tests at bending radii of 7.0 mm and 3.5 mm.

After 1,000 repeated bending results, it was confirmed that the flexibility was at a level of 90 to 95%, which is excellently suitable for actual use of smart electronic devices worn on the skin.

Figure 32 is a photograph of a flexibility test of a supercapacitor including a composite material as an electrode on a fabric substrate according to an embodiment of the present invention.

Even when fabric was used as a substrate, it was confirmed that there was no change in appearance or damage to the electrode after the bending test.

Figure 33 is a graph showing the CV profile before and after measuring the flexibility of a supercapacitor including a composite material as an electrode on a fabric substrate according to an embodiment of the present invention, and Figure 34 is a graph showing a composite material on a fabric substrate according to an embodiment of the present invention. It is a graph showing the results of electrochemical impedance spectroscopy (EIS) measurement before and after measuring the flexibility of a supercapacitor including an electrode, and Figure 35 is a graph showing the results of a supercapacitor including a composite material as an electrode on a fabric substrate according to an embodiment of the present invention. This is a graph showing energy storage performance before and after flexibility measurement.

Referring to Figures 33 to 35, the CV and EIS results in the case of bending showed somewhat reduced electrochemical redox reaction performance.

In the bending experiment, it was confirmed that the capacitance was maintained very well at a maximum of 98% after 500 bending cycles and 93% after 1000 bending cycles.

Compared to a supercapacitor with a current collector applied to an ITO/PET substrate, it showed superior CV and EIS profiles than the fabric device, and this was confirmed to be due to the continuous conductive reaction on the ITO/PET phase.

However, in the case of bending stability, it was confirmed that supercapacitors made of fabric substrates can exhibit superior performance than ITO/PET devices.

Experimental Example 7. Confirmation of dual electrolyte functionalization of supercapacitor

Thin-film supercapacitors were fabricated on fabric and ITO/PET substrates to investigate the functionality of dual electrolytes of sweat and ionic liquid.

Initial work The performance was evaluated under conditions containing only ionic liquid without sweat, and the performance of the supercapacitor was difficult to drive a mini fan.

Figure 36 is a photograph of a supercapacitor including a composite material as an electrode according to an embodiment of the present invention being worn on the human body and allowing sweat discharged into the electrolyte.

The supercapacitor element was fixed to the arm of the human body, and the performance of the dual electrolyte of sweat and ionic liquid was confirmed while the wearer sweated in an exercise device.

After exercising and sweating, the supercapacitor charging and discharging details were simultaneously recorded.

Figure 37 is a photograph of a mini-fan operating a supercapacitor including ITO/PET and a composite material on a fabric substrate as electrodes in one embodiment of the present invention, and Figure 38 is a photograph of a supercapacitor including a composite material on ITO/PET and a fabric substrate in one embodiment of the present invention. This is a photo of the LED operation of a supercapacitor including as an electrode, and Figure 39 is a photo of a thermo-hygrometer operation of a supercapacitor including ITO/PET and a composite material on a fabric substrate as electrodes in one embodiment of the present invention.

37 to 39, the performance of the supercapacitor after dual electrolyte self-recharging by sweat is shown, and the driving capacity of the mini-fan working model of the supercapacitor comprising the composite fabricated on ITO/PET film and fabric substrate. This improvement was confirmed.

Additionally, we installed a small LED and tested the performance of the temperature sensor and humidity sensor elements according to the recharge of sweat in the supercapacitor. As a result, the self-recharge efficiency by the addition of sweat in the double electrolyte was confirmed by the ITO/PET film and the fabric substrate. It was confirmed that self-charging was very efficient under the dual electrolyte conditions of the liquid liquid, making it very suitable for supercapacitors.

Meanwhile, in a working model with a supercapacitor on fabric, the ionic liquid mode required very little effort to immediately start the device, which is believed to be due to the moisture-free, completely solid electrode and electrolyte system.

After processing with sweat, all models of supercapacitors worked well in dual electrolyte mode.

These results indicate that the ITO/PET substrate can act as an excellent conductive layer in an array of thin-film supercapacitors as a current collector, and that the array of supercapacitors on fabric is also effective when applied or fixed directly on the fabric. .

The supercapacitor system was confirmed to be useful and suitable for energy storage in smart electronic devices when connected to a booster circuit or an amplified PCP circuit system.

Notable advantages are that the planar arrangement of a typical thin film device minimizes damage to the supercapacitor electrodes, and the ionic liquid mode allows the charge storage reaction to proceed even in the absence of sweat, which increases the usability of supercapacitors containing composites. It is to increase.

Experimental Example 8. Confirmation of self-charging and charging/discharging performance of supercapacitor

The performance increase effect of sweat and the performance of sweat concentration were evaluated in a self-charging supercapacitor using dual electrolytes.

The performance evaluation of the discharge ability of the sweat-based supercapacitor was evaluated according to the exposure times of 0 hours (initial), 1, 2, 5, 10, 12, 24, and 72 hours.

Two types of supercapacitors, formed on fabric and ITO/PET film substrates, were placed in a sealed glass chamber and connected to an external connection line.

Sweat was sprayed until wet, the chamber was sealed, and the temperature was maintained at 25°C. Energy performance was recorded using a Biologic workstation, and discharge current was measured via DCR Ohm readings over 1 hour using the LCR-6100 settings.

Afterwards, six units of the supercapacitor were connected in series and its usability as a power source was investigated on fabric and ITO/PET film substrates under atmospheric conditions.

Figure 40 is a graph showing the change in CV curve over sweat wetting time of a supercapacitor including a composite material as an electrode according to an embodiment of the present invention, and Figure 41 is a graph showing a change in the CV curve of a supercapacitor including a composite material as an electrode according to an embodiment of the present invention. It is a graph showing the change in electrochemical impedance spectroscopy (EIS) measurement results over time of sweat wetting of a supercapacitor including , and Figure 42 is a graph showing the change in sweat wetting of a supercapacitor including a composite material as an electrode according to an embodiment of the present invention. This is a graph showing the change in DCR value of discharge current over wetting time.

In Figure 40, the CV profile of the symmetrical device at a scanning rate of 25 mV/s is shown.

All measured CV profiles showed nearly square redox peaks, indicating the combined effect of the operation of the supercapacitor and the redox characteristics of the battery.

The potential window of the obtained CV profile increased with time under sweaty conditions, and after 10 hours of sweat treatment, the current increased and the potential window expanded to almost 2.5 V, and after 72 hours of treatment, the potential window increased. This type of supercapacitor exhibited an increased potential of 3.5 V and a high current of 40 mA.

Normal capacitance operation was observed over the entire voltage range, and it was confirmed that the performance of device current and potential voltage increased step by step.

These characteristic voltages of 3.0 V to 3.5 V correspond to unusual operating voltages in this region, and these high operating voltages for the dual electrolyte functional supercapacitor are still higher than those of any other supercapacitor reported to date.

Referring to Figure 41, the results of EIS analysis of the discharge performance based on dual electrolyte functionalization on the surfaces of fabric and ITO/PET film substrates exposed to sweat for a long time are shown.

The recorded EIS details also revealed the high conductivity and excellent electrical connection of the supercapacitor, while the EIS results of devices fabricated on fabrics and films showed a surprising increase in electrical conductivity with increasing sweat absorption time. indicated.

The supercapacitors in both fabric and ITO/PET film exhibited typical equivalent resistances.

The dependence of the phase angle as a straight line (90°) on the frequency of the device was confirmed during the duration experiment.

With the increase of sweat absorption time, the straight line increased, for example, at the EIS frequency, the phase angle increased beyond 65°, which indicates the charging response of the supercapacitor and its increase, which is reflected in the two types of supercapacitors. Both capacitors were optimized after 10 hours.

The characteristic frequency range for phase angle was somewhat similar for both fabric and ITO/PET films, meaning that both types of devices reached their optimal energy storage performance level after 10 hours of sweating.

Therefore, the supercapacitor according to an embodiment of the present invention can provide practical application of a flexible supercapacitor in an environment where sweat is emitted.

Referring to FIG. 42, the self-discharge characteristics of a supercapacitor were previously ignored, but the self-discharge characteristics of a supercapacitor device manufactured after dual electrolyte functionalization treatment including sweat were confirmed.

The DCR profile shows small and fast self-discharge characteristics for the first 5 minutes, and then the charging performance is maintained for another 60 minutes. DCR variation also indicates the charging performance of the supercapacitor over time.

After 10 hours of sweat treatment, the performance of these supercapacitors was optimized or peaked.

Details of the DCR indicate that the fabricated supercapacitor has low self-discharge characteristics, indicating its suitability for wearable electronics applications.

Meanwhile, the performance of supercapacitors manufactured on fabric and ITO/PET film according to sweat concentration was confirmed using 100% (pure sweat), 75%, 50%, 25%, and 10% diluted with water. .

The cyclic current voltage measurement results in the case diluted with sweat showed no significant difference between pure sweat and 74% diluted case for both fabric and ITO/PET film-based supercapacitors. However, the current density slightly increased at 50% concentration, and decreased at 25% and 10%.

When compared overall with the continuous charging performance, it was confirmed that different dilution concentration factors did not have a significant effect on the deviation of current density.

Therefore, it was confirmed that charging for up to 10 hours is an important factor in performance in order to maintain electrical capacity and optimized charge/discharge performance.

Experimental Example 9. Confirmation of biocompatibility of supercapacitor

The biocompatibility of the supercapacitor manufactured according to the example was confirmed.

Treatment of HT-29 cells with TREN/PEDOT/GO-Cu chelate composite in ionic liquid mode and sweat mode using SW100% (pure sweat) and sweat diluted to SW75%, SW50%, SW25% and SW10%, respectively. did.

All samples were briefly probed with HT-29 cells, cell cultures (5 Х 103 cells mL-1) were grown in 24-well plates and preserved through IC50 (22.62 μg mL-1).

Changes in cell viability were observed under a light microscope (backlight, Nikon, Eclipse TS 100) after 24 hours of growth.

MTT assay experiments and changes in cell viability for the HT-19 cell line showed excellent biocompatibility of the TREN/PEDOT/GO-Cu chelate composite, and it was confirmed that factors depending on sweat concentration did not significantly affect cell viability. did.

The self-charging supercapacitor using the prepared dual electrolyte was confirmed to be biocompatible.

Experimental Example 10. Confirmation of repeatability and pH effect

The long-term cyclical stability of the supercapacitor manufactured according to the example was evaluated following repeated use.

The initial area capacitance was maintained at more than 96% for 50,000 repetitions under self-charging conditions with dual electrolytes of sweat and ionic liquid, and 65% for supercapacitors containing TREN/PEDOT and TREN/PEDOT/GO films as electrodes. The above vestibular capacity was maintained.

It was confirmed that the supercapacitor according to the example can exhibit excellent repeatability.

Supercapacitors using ionic liquid-containing composites (TREN/PEDOT/GO-Cu) as electrodes also showed high performance, showing a capacitance retention rate of more than 80% in experiments up to 50,00 cycles.

Meanwhile, the performance of the supercapacitor was tested at various pH conditions such as pH 1, 3, 5, 6, 7, 10, and 12.

Supercapacitors fabricated on fabric and ITO/PET film substrates in two different ionic liquids and in the dual electrolyte mode of ionic liquid and sweat were adjusted to pH of the electrolyte using a buffer solution.

Current density performance as a function of pH showed that all supercapacitors rarely showed high current densities in neutral and basic pH media. The pH range of 6 to 7 and performance are suitable for human skin and can be recommended, and it can be used as a smart electronic device attached to the skin.

It was confirmed that the supercapacitor according to the example operates well in the above pH range.

The specific capacitance, cycle stability, and energy density of the supercapacitor were compared with those of conventional supercapacitors.

Most supercapacitors that use sweat are enzyme-based and operate using sweat as an electrolyte.

The supercapacitor according to the example uses a composite of PEDOT polymer and CNT, which plays an important role in increasing charge transfer without using enzymes in the electrode, and shows compatibility and suitability for a supercapacitor including a sweat-based electrode. .

In addition, when checking the performance profile of the supercapacitor according to the example, it was confirmed that the manufactured supercapacitor showed a performance increase of more than 100 times in specific capacitance.

It was confirmed that the supercapacitor according to the example shows excellent cycling stability up to 50,000 cycles. Excellent cycling performance was achieved in a flexible thin-film supercapacitor, and it was confirmed that it can exhibit high area capacitance with excellent cycling stability.

Meanwhile, the fact that the main part of the composite material (TREN/PEDOT/GO-Cu chelate) according to the example can be self-charged by ionic liquid and sweat is largely supported by metal chelate (Cu), O, S, and N elements. Furthermore, it was confirmed that the ionic liquid increases the electric double layer ability, which exhibits capacitance due to the accumulation of large charge density, through electrostatic interaction with the metal oxide surface.

Electrostatic and electrochemical exchange of cations and anions of semiconductor metal oxides such as CuO or ZnO and ionic liquids exhibited tremendous interfacial capacitance that can be used for signal amplification, and BMIM[BF ₄ ], an ionic liquid, has been used as a wearable sensing device. It was confirmed to be a stabilizing mediator for the antibody receptor probe immobilized on the surface of the modified active material.

Therefore, it was confirmed that the self-charging performance using a dual electrolyte containing sweat and ionic liquid shows that the supercapacitor device has the potential to be very suitable as a wearable skin-based electronic device.

The present invention provides a thin film-type supercapacitor capable of self-charging by dual electrolytes in which a composite material is formed as an electrode on a fabric or ITO/PET film substrate using sweat and ionic liquid. The fabricated device is arranged entirely in a planar shape to reduce damage under flexible conditions, and is a mixture of tri(2-aminoethyl)amine, poly-3,4-ethylenedioxythiophene, graphene oxide, and copper-mediated chelate. High-strength electrodes made of were arranged. These devices exhibited excellent mechanical stability and flexibility by maintaining 90% capacitance under bending radius conditions of 7.0 mm and 3.5 mm, and the supercapacitor in dual electrolyte mode, which exhibits self-charging performance by ionic liquid and sweat, is It exhibited excellent energy storage performance (up to 36 F·cm ^-2 areal capacitance and 4.5 Wh·cm ^-2 energy density).

Wearable devices containing these supercapacitors were well attached to the body during exercise to recharge electrolytes, and these supercapacitors exhibited increased current density with increasing voltage range during sweating time. In the device, sweat electrolyte mode showed excellent performance increase even when the fabric and ITO/PET substrate were very small.

The present invention is the first to disclose a supercapacitor that is self-charged by a dual electrolyte using a polymer-graphene oxide-metal chelate composite as an electrode. This supercapacitor proposes a high-power power source based on sweat and can be attached to the skin. As a wearable device, it can be installed in various smart electronic devices.

So far, the present invention has been examined focusing on the embodiments. A person skilled in the art to which the present invention pertains will understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative rather than a restrictive perspective. The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the equivalent scope should be construed as being included in the present invention.

1000: Supercapacitor
100: Current collector (substrate) 200: Electrode (composite material)
300: Electrolyte 400: Metal wire (Cu)

Claims (15)

Amine-based compounds;
conductive polymer;
graphene oxide; and
Contains metal oxides,
The amine compound, conductive polymer, and graphene oxide form a matrix, and the metal of the metal oxide forms a chelate with the matrix,
The matrix is formed by hydrogen bonding an amine-based compound and a conductive polymer in a reactor of graphene oxide.
Composites for supercapacitor electrodes.
The method of claim 1, wherein the amine compound includes tri(2-aminoethyl)amine [Tris(2-aminoethyl)amine],
The conductive polymer includes 3,4-ethylenedioxythiophene,
A composite material for a supercapacitor electrode wherein the metal oxide includes copper oxide (CuO).
The composite material for supercapacitor electrodes according to claim 1, wherein the composite material for supercapacitor electrodes has a cavity formed therein.
The composite material for supercapacitor electrodes according to claim 1, wherein the composite material for supercapacitor electrodes has a strain rate of 12% or more and a tensile strength of 22 MPa or more.
house collector;
At least one electrode stacked on the current collector;
Electrolyte imprinted on the electrode; and
It includes a metal wire provided on the upper part of the electrode,
The electrode is formed from the composite material of claim 1,
Supercapacitor.
The method of claim 5, wherein the composite material includes tris(2-aminoethyl)amine, 3,4-ethylenedioxythiophene, graphene oxide, and copper oxide ( CuO), wherein the copper forms a chelate.
The supercapacitor of claim 5, wherein the current collector includes fabric or ITO/PET.
The supercapacitor according to claim 5, wherein the electrolyte includes an ionic liquid mixed with sweat discharged from the human body.
The supercapacitor of claim 5, wherein the area capacitance of the supercapacitor is 36 F·cm ^-2 at 0.2 mA·cm ^-2 .
The supercapacitor according to claim 5, wherein the supercapacitor preserves more than 90% of its initial capacitance after 200 bending tests at bending radii of 7.0 mm and 3.5 mm.
The supercapacitor according to claim 5, wherein the CV profile voltage increases to 3.5 V according to the cyclic current voltage measurement under dual electrolyte conditions containing ionic liquid and sweat.
The supercapacitor according to claim 5, wherein the supercapacitor is capable of self-charging under electrolyte conditions using ionic liquid, sweat, or a combination thereof.
A smart wearable electronic device comprising the supercapacitor according to any one of claims 5 to 12 as a power unit.
(a) preparing a dispersion containing a metal oxide by hydrothermal synthesis of a metal oxide precursor and hydrazine;
(b) adding graphene oxide and the dispersion to a solution containing a conductive polymer and an amine compound, adding an ionic liquid as a catalyst and stirring to prepare a composite composition;
(c) drying the composite composition to obtain a composite film;
(d) attaching the composite film to a current collector; including,
Supercapacitor manufacturing method.
The method of claim 13, wherein the ionic liquid is 1-Butyl-3-methylimidazolium tetrafluoroborate.

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