KR102112664B1 - Mxene-conductive polymer composite material and supercapacitor having the mxene-conductive polymer composite material - Google Patents

Abstract

Disclosed is a Mxene-conductive polymer composite material having a porous structure. The composite material includes a conductive polymer and an anionic functional group that interacts with the conductive polymer, and includes Mxene flakes having electrical conductivity. This composite material has excellent electrical conductivity, high ion transport capacity, and excellent mechanical properties.

Description

MXENE-CONDUCTIVE POLYMER COMPOSITE MATERIAL AND SUPERCAPACITOR HAVING THE MXENE-CONDUCTIVE POLYMER COMPOSITE MATERIAL}

The present invention relates to a supercapacitor including a mexane-conducting polymer composite material having excellent electrical conductivity and excellent ion transport ability.

Aluminum electrolytic capacitors are the only capacitors used for fast charging and discharging, and can meet the requirements of next-generation flexible / wearable electronic devices such as AC filtering and power conversion.

However, conventional aluminum electrolytic capacitors have a problem in that they are not suitable for portable or wearable electronic devices because of their large volume. In addition, the conventional electric double layer capacitor using activated carbon exhibits high resistance behavior at a frequency of 1 Hz or higher, and thus has limitations in application to devices requiring high output.

To solve this problem, the development of ultra-small high-frequency supercapacitors began using nano-structured carbon to replace alternating current filtering of electrolytic capacitors, and was carried out with conductive polymers and metal oxide / carbon composites, but with high capacitance per unit volume. Fabrication of a large area flexible device remains a big challenge.

One object of the present invention is to provide a mexane-conducting polymer composite material having excellent electrical conductivity and ion transporting ability and excellent mechanical properties by including a mexane flake and a conductive polymer having excellent electrical conductivity and having a porous structure.

Another object of the present invention is to provide a supercapacitor comprising the above-mentioned mexane-conducting polymer composite material as an electrode material.

Mxene-conductive polymer composite material according to an embodiment of the present invention includes a conductive polymer; And an anionic functional group that interacts with the conductive polymer, and includes an electrically conductive mexane flake, and has a porous structure.

In one embodiment, the mexane flakes are Ti ₂ C, (Ti _0.5 , Nb _0.5 ) ₂ C, V ₂ C, Nb ₂ C, Mo ₂ C, Ti ₃ C ₂ , Ti ₃ CN, Zr ₃ C ₂ , Hf ₃ C ₂ , Ti ₄ N ₃ , Nb ₄ C ₃ , Ta ₄ C ₃ , Mo ₂ TiC ₂ , Cr ₂ TiC ₂ and Mo ₂ Ti ₂ C ₃ . .

In one embodiment, the anionic functional group may include one or more selected from the group consisting of a hydroxy group (-OH), a carbonyl group (= O) and a fluorine group (-F).

In one embodiment, at least some of the monomers of the conductive polymer may be oxidized by interaction with the anionic functional group.

In one embodiment, the conductive polymer is poly (3,4-ethylenedioxythiophene) (PEDOT), polyphenylene, polythiophene, poly (alkylthiophene) ), Polyfuran, polypyrrole, poly (phenylenevinylene), poly (thienylenevinylene), and polyacetylene. The above polymer compound may be included, and in this case, the conductive polymer may include one monomer selected from the group consisting of the following Chemical Formulas 2-1 to 2-9.

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Formula 2-4]

[Formula 2-5]

[Formula 2-6]

[Formula 2-7]

[Formula 2-8]

[Formula 2-9]

In one embodiment, the conductive polymer comprises a poly (3,4-ethylenedioxythiophene) (PEDOT) molecule and a polystyrene sulfonate (PSS) molecule that interacts with the PEDOT molecule, and at least some of the monomers of the PEDOT molecule are It may have an oxidized quinoid structure. In one embodiment, the PEDOT molecule may include a monomer of a benzoid structure (Benziod structure) and a monomer of the quinoid structure in a neutral state, or may include only the monomer of the quinoid structure.

In one embodiment, the mexane (Mxene) -conductive polymer composite material is 30 parts by weight to 150 parts by weight, preferably 40 parts by weight to 60 parts by weight, based on 100 parts by weight of the conductive polymer can do.

Super capacitor according to an embodiment of the present invention includes a first electrode; A second electrode spaced apart from the first electrode 110A and disposed to face each other; And an electrolyte disposed between the first electrode and the second electrode, wherein at least one of the first electrode and the second electrode 110B is a conductive polymer; And an anionic functional group that interacts with the conductive polymer, and includes an electrically conductive Mxene flake, and may be formed of a Mxene-conductive polymer composite material having a porous structure.

In an embodiment, the electrolyte may include a first polymer network formed of a first polymer including first main chains cross-linked in a network; It is formed of a second polymer that is cross-linked in a network shape and is at least partially chemically bonded to the first polymer network, and is more flexible than the first polymer, and surrounds at least a portion of the first polymer network A second polymer network arranged so as to be arranged; And it may be formed of a gel electrolyte comprising a liquid electrolyte carried inside the double cross-linked network defined by the first and second polymer networks. In this case, the first polymer may have higher strength than the second polymer.

In one embodiment, the first polymer is polyvinyl alcohol (Polyvinyl alcohol), polyacrylamidomethylpropanesulfonic acid (poly2-Acrylamido-2-methyl-1-propanesulfonic acid), polyacrylic acid (Polyacrlic Acid), polypyrrole It includes at least one selected from the group consisting of poly (N-pyrrolidone) and polysaccharide, and the second polymer includes hydroxyethyl methacrylate, acryl amide and It may include one or more polymers selected from the group consisting of dimethylacrylamide. For example, the second polymer is methylenebisacrylamide, ethylene glycol dimethacrylate, ethylene glycol diglycidyl ether, hexanediol diacrylate , Hydroxyethyl methacrylate chains cross-linked by one or more selected from the group consisting of diallyl acrylamide (N, N-diallylacrylamide) and divinylbenzene.

In one embodiment, the degree of crosslinking of the second polymer network may be lower than that of the first polymer network.

In one embodiment, the chain length of the second polymer network may be longer than the chain length of the first polymer network.

In one embodiment, the liquid electrolyte may include an ionic liquid or an organic electrolyte.

In one embodiment, the liquid electrolyte includes the ionic liquid, and each of the first and second polymer networks may include a polar functional group for dissociating cations and anions of the ionic liquid.

According to the Mxene-conducting polymer composite material of the present invention, it contains a Mexene flake and a conductive polymer having excellent electrical conductivity, and the anionic functional group of the Mexene flake oxidizes at least some of the monomers of the conductive polymer Since it transitions to a state, it can not only have excellent electrical activity ability, but also excellent electrical conductivity. In addition, since the Mxene-conductive polymer composite material has a porous structure, ion transport capacity is very excellent.

1A and 1B are planar and cross-sectional SEM images of a Mexane-PEDOT: PSS composite, which is an embodiment of the Mxene-conductive polymer composite material of the present invention.
2 is a view for explaining the monomer oxidation mechanism in the mexane-PEDOT: PSS complex.
3 is a cross-sectional view illustrating a super capacitor according to an embodiment of the present invention.
4 is a view showing a double-crosslinking network synthesis reaction using PVA and hydroxyethyl methacrylate (HEMA).
5 shows XPS data for Ti3C2, Ti3C2-PEDOT: PSS complex and PEDOT: PSS.
6A to 6C are graphs showing the CV curve, the GCD curve, and the charge / discharge efficiency of the supercapacitor ('MP12') manufactured according to the embodiment, respectively.
7A to 7E are units according to the scanning speed for the first supercapacitor ('MP11') and the second supercapacitor ('MP12') and the supercapacitor ('Ti3C2') according to the comparative example. The capacitance per area, the capacitance per unit volume according to the scanning speed, the phase angle according to the frequency, the Nyquist plot, and the capacitance per unit area according to the frequency, respectively.
FIG. 8 shows CV curves measured at different bending angles for a supercapacitor ('MP12') prepared according to an example using a composite in which the weight ratio of Ti3C2 and PEDOT: PSS is 1: 2.
FIG. 9 shows AC line filtering characteristics through the supercapacitor measured at different frequencies for a supercapacitor ('MP12') prepared according to an embodiment using a composite in which the weight ratio of Ti3C2 and PEDOT: PSS is 1: 2. It is a graph to show.
FIG. 10 shows capacitance retention and charge / discharge efficiency per unit area per test cycle measured for a supercapacitor ('MP12') prepared according to an embodiment using a composite in which the weight ratio of Ti3C2 and PEDOT: PSS is 1: 2. It is a graph.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention can be applied to various changes and may have various forms, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure form, and it should be understood as including all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "include" or "have" are intended to indicate the presence of features, steps, actions, components, parts or combinations thereof described in the specification, one or more other features or steps. It should be understood that it does not preclude the existence or addition possibility of the operation, components, parts or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

1A and 1B show planar and cross-sectional SEM images, respectively, of the Mexane-PEDOT: PSS composite, which is an example of the Mxene-conductive polymer composite material of the present invention, and FIG. 2 shows the Mexane-PEDOT: PSS. It is a diagram for explaining the mechanism of monomer oxidation in the complex.

Referring to Figures 1a, 1b and 2, the mexane (Mxene) -conducting polymer composite material according to an embodiment of the present invention comprises a conductive polymer and a mexane flake having an anionic functional group interacting with the conductive polymer It may include, and may have a porous three-dimensional network structure.

The mexane flake may have a single molecular layer structure or a multilayer structure within several molecular layers so that it may have electrical conductivity, and the mexane may be represented by the following Chemical Formula 1.

[Formula 1]

M _{n + 1} X _n T _x

In Chemical Formula 1, M represents one or more transition metals, X represents carbon or nitrogen, and T represents an anionic functional group. And n can be 1, 2 or 3.

In one embodiment, the mexane is Ti ₂ C, (Ti _0.5 , Nb _0.5 ) ₂ C, V ₂ C, Nb ₂ C, Mo ₂ C, Ti ₃ C ₂ , Ti ₃ CN, Zr ₃ C ₂ , Hf ₃ C ₂ , Ti ₄ N ₃ , Nb ₄ C ₃ , Ta ₄ C ₃ , Mo ₂ TiC ₂ , Cr ₂ TiC ₂ , Mo ₂ Ti ₂ C ₃ and the like. In one embodiment, the mexane flake may have a size of about 50 to 1000 nm, preferably about 50 to 200 nm. Meanwhile, the anionic functional group may include at least one selected from a hydroxy group (-OH), a carbonyl group (= O), a fluorine group (-F), and the like, and may be bound to the surface of the mexane flake.

The mexane flake may be prepared from a compound on Max (MAX) represented by the following Chemical Formula 2, and a known method of manufacturing a mexane flake may be applied without limitation in order to prepare the mexane flake.

[Formula 2]

M _{n + 1} AX _n

In Chemical Formula 2, M represents one or more transition metals, A represents a group 13 or 14 element of the periodic table, and X represents carbon or nitrogen.

In one embodiment, in order to prepare the mexane flake, the compound powder on the max (MAX) is immersed in an aqueous hydrofluoric acid (HF) solution to remove the interlayer bonding element A to prepare a multi-layered mexane flake, Subsequently, the multi-layered mexane flakes are immersed in an organic solvent containing guest molecules such as dimethyl sulfoxide (DMSO), hydrazine, and urea to intercalate the guest molecules, followed by centrifugation to perform single separation. An electrically conductive mexane flake composed of a molecular layer or several molecular layers can be prepared.

The conductive polymer may be a polymer compound having electrical conductivity.

In one embodiment, the conductive polymer may include at least one monomer oxidized by interaction with the anionic functional group of the mexane. For example, the conductive polymer is poly (3,4-ethylenedioxythiophene) (PEDOT), polyphenylene, polythiophene, poly (alkylthiophene), One or more polymer compounds selected from polyfuran, polypyrrole, poly (phenylenevinylene), poly (thienylenevinylene), polyacetylene, and the like It may include, at least some of the monomers of the conductive polymer may have an electrochemical structure corresponding to the oxidation state (oxidation state) as shown in Table 1. For example, in the Mxene-conductive polymer composite material according to the embodiment of the present invention, all of the monomers of the conductive polymer may be in an oxidized state, or only some of them may be in an oxidized state.

conductive polymer neutral state oxidation state poly (3,4-ethylenedioxythiophene)
<PEDOT>

polyphenylene

polythiophene

poly (alkylthiophene)

polyfuran

polypyrrole

poly (phenylenevinylene)

poly (thienylenevinylene)

polyacetylene

In one embodiment, as shown in FIG. 2, the Mxene-conductive polymer composite material according to the embodiment of the present invention has a hydroxy group (-OH), a carbonyl group (= O), and a fluorine group on the surface. It may be a composite material of a titanium carbide (Ti ₂ C, Ti ₃ C ₂ ) flake and PEDOT: PSS to which an anionic functional group such as (-F) is bonded, and in this case, as described in Reaction Scheme 1 below, the anionic The functional group and the PEDOT molecule interact to oxidize the benzoid structure of the PEDOT to be converted into a quinoid structure, whereby the electrical activity and conductivity of the PEDOT: PSS can be improved. .

[Scheme 1]

The mexane (Mxene) -conducting polymer composite material according to an embodiment of the present invention can be prepared by adding a conductive polymer solution to the mexane flake colloidal solution and stirring at room temperature, and may have a porous three-dimensional network structure. . For example, the Mxene-conductive polymer composite material may include internal pores having a size of about 2 to 50 nm, and the ratio of the internal pores, that is, the porosity, may be changed by adjusting the content of the Mexane flakes. have.

In one embodiment, the Mxene (Mxene) -conductive polymer composite material may include about 30 parts by weight to 150 parts by weight of the Mexane flake based on 100 parts by weight of the conductive polymer. When the content of the mexane flake is less than 30 parts by weight based on 100 parts by weight of the conductive polymer, the proportion of the monomers that have been converted to the oxidized state among the monomers of the conductive polymer is not high, and the internal porosity decreases, thereby reducing the A problem that the electrical activity or ion transport capacity improvement is not high may occur, and when the content of the mexane flake exceeds 150 parts by weight, the electrical activity of the oxidized state structure in the composite material is lowered and the porosity is excessively increased, which is required. In order to achieve performance, there may be a problem that the thickness of the composite film needs to be increased. For example, the Mxene-conductive polymer composite material may include about 40 parts by weight to 60 parts by weight of the Mexane flake based on 100 parts by weight of the conductive polymer.

According to the Mxene-conducting polymer composite material of the present invention, it contains a Mexene flake and a conductive polymer having excellent electrical conductivity, and the anionic functional group of the Mexene flake oxidizes at least some of the monomers of the conductive polymer Since it transitions to a state, it can not only have excellent electrical activity ability, but also excellent electrical conductivity. In addition, since the Mxene-conductive polymer composite material has a porous structure, ion transport capacity is very excellent.

3 is a cross-sectional view for explaining a supercapacitor according to an embodiment of the present invention, and FIG. 4 is a view showing a double-crosslinking network synthesis reaction using PVA and hydroxyethyl methacrylate (HEMA).

Referring to FIG. 3, the supercapacitor 100 according to an embodiment of the present invention may include a first electrode 110A, a second electrode 110B, and an electrolyte 120.

The first electrode 110A and the second electrode 110B may be disposed to face each other in a spaced apart state.

In one embodiment, at least one of the first electrode 110A and the second electrode 110B may be formed of the above-described mexane-conductive polymer composite material. For example, both the first electrode 110A and the second electrode 110B may be formed of the mexane-conductive polymer composite material. Alternatively, the first electrode 110A may be formed of the mexane-conductive polymer composite material, and the second electrode 110B may be formed of a known porous carbon material.

On the other hand, of the first electrode (110A) and the second electrode (110B) of the electrode formed of the material of the mexane-conductive polymer composite may have a film structure of about 100 to 400 nm thick.

The electrolyte 120 may be disposed between the first electrode 110A and the second electrode 110B, and ions may be formed of a conductive material. The material of the electrolyte 120 is not particularly limited, and a known electrolyte material can be applied without limitation.

In one embodiment, as shown in Figure 4, the electrolyte 120 may be formed of a gel electrolyte including a first polymer network, a second polymer network and a liquid electrolyte.

The first polymer network may be formed of a relatively high toughness first polymer. The first polymer network may have a structure in which first main chains are cross-linked to each other. In one embodiment, the first polymer network is preferably about 10 × 10 ^-- mol / cm³ or more in order to realize high toughness and high strength properties.

In one embodiment, the first polymer is polyvinyl alcohol (Polyvinyl alcohol), polyacrylamidomethylpropanesulfonic acid (poly2-Acrylamido-2-methyl-1-propanesulfonic acid, PAMPS), polyacrylic acid (Polyacrlic Acid), Polypyrrolidone (Poly (N-pyrrolidone)), polysaccharide (Polysaccharide), and the like, may be formed of a polymer material having relatively high strength and high toughness. The polysaccharide may include polymers such as alginate, gellan gum, and agarose.

In one embodiment, the first polymer network may be formed by polymerizing linear polymer chains and then crosslinking them through a radical recombination reaction using a thermal initiator. In this case, K2S2O8 may be used as the initiator. For example, when the first polymer network is formed of polyvinyl alcohol (PVA), argon gas is used to remove dissolved oxygen after preparing a polymer solution by mixing linear polyvinyl alcohol, K ₂ S ₂ O ₈ and distilled water. And then stirred at a temperature of about 80 ° C. for 3 hours to crosslink the linear polyvinyl alcohols to prepare the first polymer network.

In one embodiment, the degree of cross-linking of the first polymer network may be higher than that of the second polymer network. By the first polymer network, the gel electrolyte according to the present invention may have characteristics of high mechanical strength and high toughness. In one embodiment, the first polymer network may have a crosslinking degree of about 10 × 10 ^- ⁴mol / cm³ to 20 × 10 ^- ⁴mol / cm³.

The second polymer network may be formed of a second polymer having higher flexibility than the first polymer constituting the first polymer network. In one embodiment, the second polymer network may include second main chains cross-linked with each other in a network, and at least a portion of the second main chains are chemically chemically connected to the first polymer network. Can be combined. That is, the first polymer network and the second polymer network may form a cross-through double cross-linked network. In one embodiment, the degree of crosslinking of the second network may be about 10 ^- ⁴mol / cm³ or less. In one embodiment, the second polymer may include polymers such as hydroxyethyl methacrylate (HEMA), acryl amide, and dimethylacrylamide.

In one embodiment, the double cross-linked network of the first polymer network and the second polymer network expands the first polymer network through solvent swelling, and then the expanded first polymer network in distilled water, the second By mixing and reacting a monomer, a crosslinking agent, and an initiator for forming a polymer, the second polymer network chemically coupled to the first polymer network can be prepared. In this case, the crosslinking agent may include an ethoxysilane-based, acrylic-based, or epoxy-based compound, but is not limited thereto. For example, the crosslinking agent is methylenebisacrylamide (MBAA), ethylene glycol dimethacrylate, ethylene glycol diglycidyl ether, hexanediol diacrylate , Diallyl acrylamide (N, N-diallylacrylamide), divinylbenzene (divinylbenzene), and the like. As the initiator, a known polymerization initiator can be applied without limitation. For example, the initiator may include K ₂ S ₂ O ₈ .

In one embodiment, the degree of crosslinking of the second polymer network may be lower than that of the first polymer network, and the chain length of the second polymer network may be longer than the chain length of the first polymer network.

The double crosslinked network formed by the first and second polymer networks may form an internal space in which the liquid electrolyte can be supported, and the liquid electrolyte may be supported in an inner space formed by the double crosslinked network. .

In one embodiment, the liquid electrolyte may include an ionic liquid, an organic electrolyte, an aqueous electrolyte, and the like. As the ionic liquid, a known material can be applied without limitation, and for example, the ionic liquid is one selected from BIMI: BF4, EMIM: TFSI, EMIM: BF4, etc., which are imidazolium-based ionic liquids. Can be. As the organic electrolyte, a known organic electrolyte can be applied without limitation, for example, the organic electrolyte is an organic solvent and LiBF ₄ , LiClO ₄ , LiPF ₆ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiC (SO ₂ CF ₃ ) ₂ , LiB (C ₂ H ₅ ) _4, and the like. As the water-based electrolyte, a known water-based electrolyte can be applied without limitation, and, for example, the water-based electrolyte may include an aqueous solution such as sulfuric acid, phosphoric acid and potassium hydroxide.

Meanwhile, when the liquid electrolyte includes an ionic liquid, each of the first and second polymer networks may include a polar functional group for dissociating cations and anions of the ionic liquid. For example, the polar functional group is an alcohol group (-OH), an amide group (-CONH ₂ ), a carboxyl group (-COOH), a ketone group (-CO-), an aldehyde group (-CHO), an amine group (-NH ₂ ) , Ester group (-COOR), ether group (-O-), and the like. As such, when the first and second polymer networks include many polar functional groups, ion conductivity may be significantly improved.

In the gel electrolyte according to the embodiment of the present invention, the first polymer may be included in a proportion of about 5 to 15 wt%, the second polymer may be included in a proportion of about 25 to 35 wt%, and the liquid phase The electrolyte may be included in a ratio of about 55 to 65 wt%.

According to the gel electrolyte of the present invention, since the first polymer network providing high strength and toughness and the second polymer network providing high flexibility and elasticity are cross-linked with each other to support the liquid electrolyte inside the double-crosslinked network, external stress is generated. When applied, the stress can be effectively dissipated by the first polymer network having high strength and toughness, as well as the flexibility and reversible deformability provided by the second polymer network. In addition, due to the improved mechanical properties of the double crosslinked network, more liquid electrolyte can be supported inside the double crosslinked network, and as a result, the gel electrolyte simultaneously provides a wide range of potential windows and improved ion conductivity. can do.

Meanwhile, the supercapacitor 100 according to an embodiment of the present invention includes a first current collector 130A electrically connected to the first electrode 110A and a second current collector electrically connected to the second electrode 110B ( 130B), and the structure and material of a known supercapacitor current collector can be applied without limitation to the first current collector 130A and the second current collector 130B. Omitted.

Hereinafter, specific examples and experimental examples according to the present invention will be described. However, the following examples are only some embodiments of the present invention, and the scope of the present invention is not limited to the following examples.

[Mexane-PEDOT: Preparation of PSS complex]

After slowly adding 1 g of a carbide compound of Ti ₃ AlC _{2 in a} phase of 1 g to a 50 ml aqueous solution of 50% HF (Fluoric acid), the mixture was stirred at room temperature for 18 hours, and then the residue was separated and discarded and washed with distilled water. After washing, the process of centrifugation at 3500 rpm for 2 minutes was repeated until the pH of the suspension became 6.

Subsequently, the precipitated slurry was lyophilized to obtain a multilayer of Ti ₃ C ₂ .

Then, the obtained multilayer Ti ₃ C ₂ was mixed with DMSO and stirred at room temperature for 24 hours to extend the interlayer spacing of the multilayer Ti ₃ C ₂ through intercalation, and then the collected solution was 3500 rpm. DMSO was isolated by centrifugation at 5 min.

For the separation of the multi-layer Ti3C2 with a gap between layers, ultrasonic treatment was performed while injecting argon gas in an ice bath, and after ultrasonic treatment, the solution was centrifuged at 3500 rpm for 1 hour to remove the unremoved material and collect the supernatant. The collected supernatant was evaporated from the solvent through lyophilization, and the remaining Ti ₃ C ₂ flakes were used.

A PEDOT: PSS solution was added to the colloidal solution of Ti ₃ C ₂ and stirred at room temperature for 2 hours to synthesize a Ti ₃ C ₂ / PEDOT: PSS colloidal solution. At this time, the weight ratio of Ti ₃ C ₂ to PEDOT: PSS was adjusted to 1: 1 ('MP11') and 1: 2 ('MP12').

[Production of electrolyte]

After introducing PVA (polyvinyl alcohol) chains and the initiator K2S2O8 into distilled water and mixing to prepare a first polymer solution, argon gas was injected to remove dissolved oxygen. Subsequently, for a homogeneous concentration, the first polymer solution was stirred for 3 hours at a temperature of 80 ° C. until the viscosity of the polymer solution reached a maximum value, and then the reaction was stopped and the first polymer solution was cooled to room temperature. , A first polymer network, a PVA network, was prepared.

Subsequently, a second polymer solution was prepared by mixing HEMA (hydroxyethyl methacrylate) monomer, MBAA (Methylenebisacrylamide) crosslinker, initiator K2S2O8, and ionic liquid EMIM: BF4 in distilled water together with the PVA network. Subsequently, the second polymer solution was injected with argon gas and vigorously stirred at a temperature of 80 ° C. for 20 minutes to prepare a gel electrolyte.

Subsequently, the second polymer solution in the gel state was placed in a vacuum oven at 70 ° C. and heat treated to remove water from the second polymer solution in the gel state.

[Production of Super Capacitors]

After coating a gold (Au) current collector on a PET film, a supercapacitor was prepared by inserting the gel electrolyte between two electrode plates on which an electrode was formed of the mexane-PEDOT: PSS composite. In the supercapacitor, since the gel electrolyte also functions as a separator, a separate separator was not applied.

[Experimental Example]

5 shows XPS data for Ti3C2, Ti3C2-PEDOT: PSS complex and PEDOT: PSS.

First, referring to FIGS. 1A, 1B, 2 and 5, when the synthesis method of the embodiment is followed, the complexation of Ti3C2 and PEDOT: PSS is successfully achieved, and the prepared Ti3C2-PEDOT: PSS complex has a porous structure. can confirm.

6A to 6C are graphs each showing a CV capacitor, a GCD curve, and a charge / discharge efficiency of a supercapacitor prepared according to an embodiment. It was prepared using a 1: 2 complex.

Referring to Figures 6a to 6c, it can be seen that the supercapacitor ('' manufactured according to the embodiment has excellent voltage-current characteristics and excellent capacitance exhibiting high current density. Specifically, shown in Figure 6a As shown in FIG. 6B and FIG. 6C, it shows a rectangular current-voltage graph without resistance behavior from a slow scanning speed of 0.1 V / s to a fast scanning speed of 1000 V / s, and the rate characteristics of the supercapacitor are excellent. As shown in the figure, it can be seen that the graph shows a symmetrical shape, so that the charge and discharge ratios of the supercapacitors are almost identical and reversible, indicating a high Coulomb efficiency value.

7A to 7E are capacities per unit area and the scanning speed according to the scanning speed for the first supercapacitor '' and the second supercapacitor '' and the supercapacitor '' according to the comparative example manufactured according to the embodiment. The capacitance per unit volume according to, the phase angle according to the frequency, the Nyquist plot and the capacitance per unit area according to the frequency are respectively shown.

First, referring to FIGS. 7A and 7B, the first supercapacitor '' and the second supercapacitor '' compared to the supercapacitor ('' according to a comparative example) have a capacitance per unit area according to a scanning speed and a scanning speed It can be seen that the capacitance per unit volume is excellent.

Subsequently, referring to FIGS. 7C to 7E, the second supercapacitor '' is more capacitive than the first supercapacitor '', has lower equivalent series resistance, and has a capacity retention rate in a wider frequency range. It can be confirmed that it is excellent, and the second supercapacitor (&quot;) shows a large phase angle of 79.1 degrees at a frequency of 120 Hz, which shows excellent capacitor behavior.

Therefore, it is determined that the composite material preferably contains the mexane flakes in an amount of about 40 parts by weight or more and 60 parts by weight or less based on 100 parts by weight of the conductive polymer.

FIG. 8 shows CV curves measured at different bending angles for a supercapacitor (') prepared according to an example using a composite in which the weight ratio of Ti3C2 to PEDOT: PSS is 1: 2.

Referring to FIG. 8, it can be seen that the supercapacitor maintains a constant performance even at different bending angles.

FIG. 9 is a graph showing alternating current line filtering characteristics through the supercapacitor measured at different frequencies for a supercapacitor ('') prepared according to an embodiment using a composite in which the weight ratio of Ti3C2 to PEDOT: PSS is 1: 2. to be.

Referring to FIG. 9, it can be seen that, at different frequencies, the AC line filtering effect of the supercapacitor is excellent.

FIG. 10 is a graph showing capacitance retention and charge / discharge efficiency per unit area per test cycle measured for a supercapacitor ('' measured according to an example) using a composite in which the weight ratio of Ti3C2 to PEDOT: PSS is 1: 2. .

Referring to FIG. 10, it can be seen that the supercapacitor maintains capacitance and charge / discharge efficiency even after several charge / discharge cycles.

Although described above with reference to the preferred embodiments of the present invention, those skilled in the art may variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can.

100: supercapacitor 110A: first electrode
110B: second electrode 120: electrolyte

Claims (34)

delete delete delete delete delete delete delete delete delete delete delete A first electrode;
A second electrode spaced apart from the first electrode and disposed to face each other; And
And an electrolyte disposed between the first electrode and the second electrode,
At least one of the first electrode and the second electrode is a conductive polymer; And an anionic functional group that interacts with the conductive polymer, and includes an electrically conductive Mxene flake, and is formed of a Mxene-conductive polymer composite material having a porous structure,
The electrolyte may include a first polymer network formed of a first polymer including first main chains cross-linked in a network; It is formed of a second polymer that is cross-linked in a network shape and is at least partially chemically bonded to the first polymer network, and is more flexible than the first polymer, and surrounds at least a portion of the first polymer network A second polymer network arranged so as to be arranged; And a gel electrolyte having a liquid electrolyte carried inside a double crosslinked network defined by the first and second polymer networks. The method of claim 12,
The electrode formed of the Mxene-conductive polymer composite material among the first electrode and the second electrode is characterized in that the mexane flake comprises 40 parts by weight to 60 parts by weight based on 100 parts by weight of the conductive polymer. To do, super capacitor. The method of claim 13,
The electrode formed of the Mxene-conductive polymer composite material has a thickness of 100 to 400 nm, a supercapacitor. delete The method of claim 12,
The first polymer is characterized in that it has a higher strength than the second polymer, a super capacitor. The method of claim 16,
The first polymer is polyvinyl alcohol (Polyvinyl alcohol), polyacrylamidomethylpropanesulfonic acid (poly2-Acrylamido-2-methyl-1-propanesulfonic acid), polyacrylic acid (Polyacrlic Acid), polypyrrolidone (Poly (N- pyrrolidone)) and polysaccharides (Polysaccharide), and one or more selected from the group consisting of,
The second polymer is hydroxyethyl methacrylate (hydroxyethyl methacrylate), characterized in that it comprises at least one polymer selected from the group consisting of acryl amide (acryl amide) and dimethylacrylamide (dimethylacrylamide), super capacitor. The method of claim 12,
The second polymer is methylenebisacrylamide, ethylene glycol dimethacrylate, ethylene glycol diglycidyl ether, hexanediol diacrylate, diallyl acrylic Supercapacitors, characterized in that it comprises hydroxyethyl methacrylate chains crosslinked by one or more selected from the group consisting of amide (N, N-diallylacrylamide) and divinylbenzene. The method of claim 12,
The degree of crosslinking of the second polymer network is lower than that of the first polymer network. The method of claim 12,
The supercapacitor, characterized in that the chain length of the second polymer network is longer than the chain length of the first polymer network. The method of claim 12,
The liquid electrolyte is characterized in that it comprises an ionic liquid (ionic liquid) or an organic electrolyte, a super capacitor. The method of claim 21,
The liquid electrolyte includes the ionic liquid,
Each of the first and second polymer networks includes a polar functional group for dissociating cations and anions of the ionic liquid, a supercapacitor. The method of claim 14,
The first electrode and the second electrode are formed of the Mxene-conductive polymer composite material,
Super capacitor characterized in that it exhibits a phase angle of 79.1 ° or more at a frequency of 120 Hz. The method of claim 23,
Supercapacitor, characterized in that charging and discharging is possible at a scanning speed of 1000 V / s or more.
The method of claim 12,
The mexane flakes are selected from the group consisting of Ti2C, (Ti0.5, Nb0.5) 2C, V2C, Nb2C, Mo2C, Ti3C2, Ti3CN, Zr3C2, Hf3C2, Ti4N3, Nb4C3, Ta4C3, Mo2TiC2, Cr2TiC2 and Mo2Ti2C3 Super capacitor, characterized in that formed of a material. The method of claim 12,
The anionic functional group is a super capacitor, characterized in that it comprises at least one selected from the group consisting of a hydroxy group (-OH), a carbonyl group (= O) and a fluorine group (-F). The method of claim 12,
At least some of the monomers of the conductive polymer are characterized by being oxidized by interaction with the anionic functional group, super capacitor. The method of claim 27,
The conductive polymer is poly (3,4-ethylenedioxythiophene) (PEDOT), polyphenylene, polythiophene, poly (alkylthiophene), polyfuran ), Comprising one or more polymer compounds selected from the group consisting of polypyrrole, poly (phenylenevinylene), poly (thienylenevinylene) and polyacetylene Characterized in that, super capacitor. The method of claim 28,
The conductive polymer is characterized in that it comprises a monomer selected from the group consisting of the following formulas 2-1 to 2-9, supercapacitors:
[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Formula 2-4]

[Formula 2-5]

[Formula 2-6]

[Formula 2-7]

[Formula 2-8]

[Formula 2-9]

The method of claim 27,
The conductive polymer includes a poly (3,4-ethylenedioxythiophene) (PEDOT) molecule and a polystyrene sulfonate (PSS) molecule that interacts with the PEDOT molecule,
Supercapacitors, characterized in that at least some of the monomers of the PEDOT molecule has an oxidized quinoid structure. The method of claim 30,
The PEDOT molecule is characterized in that it comprises a monomer of the benzoid structure (Benziod structure) and the quinoid structure of the neutral state, or only the monomer of the quinoid structure, supercapacitor. The method of claim 12,
The mexane flake based on 100 parts by weight of the conductive polymer is characterized in that it contains 30 parts by weight to 150 parts by weight, super capacitor. The method of claim 32,
The mexane flake based on 100 parts by weight of the conductive polymer, characterized in that contained from 40 parts by weight to 60 parts by weight, super capacitor. The method of claim 32,
The Mxene (Mxene) -conducting polymer composite material is characterized in that it contains 2 to 50 nm of internal pores, a super capacitor.

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