KR20190087088A - Super capacitor and method of producing the same - Google Patents

Abstract

A supercapacitor according to an embodiment comprises: a first electrode; a second electrode spaced apart from the first electrode; a separator disposed between the first electrode and second electrode; and an electrolyte solution for impregnating the first electrode, second electrode and the separator. At least one of the first electrode and second electrode includes an electrode mixture layer containing an active material. The active material includes a carbon material including a plurality of pores mixed with crystalline and amorphous. The particle size (D50) of the active material is 4 μm to 6 μm. In addition, a method for manufacturing a supercapacitor according to an embodiment comprises the steps of: preparing a carbon material; heat-treating the carbon material; activating the heat-treated carbon material to form an active material; and forming an electrode. The step of forming the electrode a step of forming an electrode mixture layer by mixing the active material, a binder and a conductive material on a current collector. The active material includes a carbon material including a plurality of pores mixed with crystalline and amorphous. The particle size (D50) of the active material is 4 μm to 6 μm (particle size (D50): particle size when a cumulative volume ratio is 50% in a curve for cumulative particle size distribution of the active material). According to the present invention, electrical characteristics can be increased.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a super capacitor,

The present invention relates to a supercapacitor capable of improving electrical characteristics and a method of manufacturing the same.

Recently, interest in environmentally friendly and high performance fuel cells has been increasing due to the depletion of fossil fuels.

The electrochemical devices include a lithium ion secondary battery (LIB) and a super capacitor. The super capacitor includes a pseudo capacitor, a hybrid capacitor, and an electric double layer capacitor (EDLC) ).

The pseudo capacitor is a capacitor that stores energy by faradaic oxidation and reduction reactions at the electrode and electrolyte interface, and the hybrid capacitor is a capacitor using different asymmetric electrodes for the positive and negative electrodes. For example, one of the positive electrode and the negative electrode of the hybrid capacitor includes activated carbon containing carbon as an active material for high capacity implementation, and the other electrode includes an oxide such as a metal oxide as an active material for realizing high output, It is a capacitor that can realize high power and high capacity characteristics. That is, the hybrid capacitor is a capacitor using a chemical reaction and a surface chemical reaction.

Unlike a battery using a chemical reaction, the electric double layer capacitor utilizes a charge phenomenon by ion movement or surface chemical reaction. The electric double layer capacitor uses a carbon material such as activated carbon as an active material and has an intermediate characteristic between an electrolytic capacitor and a secondary battery. Accordingly, it is possible to perform rapid charging and discharging, have high efficiency, and can be used semi-permanently. Accordingly, the electric double layer capacitor occupies more than 80% of the entire super capacitor market, and has attracted attention as an energy storage device that can replace a secondary battery.

In particular, an electrode of a supercapacitor using a carbon material such as activated carbon as an active material is manufactured from a composition for forming an electrode including the active material, the conductive material and the binder, and the produced electrode has a change in electric characteristics depending on the density of the active material . For example, when the density of the active material is relatively low, there is a problem that the overall capacitance is decreased. When the density of the active material is relatively high, the resistance is increased and the electrical characteristics are deteriorated.

That is, as the particle size of the active material is not uniform, the electrical characteristics of the electrode may deteriorate, and the overall electrostatic capacity of the supercapacitor including the electrode may be reduced. Accordingly, the energy density and the power density of the super capacitor are degraded.

Therefore, a new super capacitor capable of solving the above problems is required.

Embodiments provide a method of manufacturing a supercapacitor and a supercapacitor capable of improving the density of the active material by optimizing the volume ratio of the active material to the particle size and size of the active material.

In addition, the embodiment is intended to provide a method of manufacturing a super capacitor and a supercapacitor which can reduce the resistance of the electrode and improve the capacitance.

In addition, embodiments provide a method of manufacturing a super capacitor and a supercapacitor capable of improving energy density and power density.

A supercapacitor according to an embodiment includes a first electrode, a second electrode disposed apart from the first electrode, a separation membrane disposed between the first electrode and the second electrode, and a first electrode, a second electrode, Wherein at least one of the first electrode and the second electrode includes an electrode mixture layer containing an active material, and the active material contains a plurality of pores in which crystalline and amorphous materials are mixed, Carbon material, and the particle size (D50) of the active material is 4 占 퐉 to 6 占 퐉.

The method of manufacturing a supercapacitor according to an embodiment includes the steps of preparing a carbon material, heat-treating the carbon material, activating the heat-treated carbon material to form an active material, and forming an electrode, Forming an electrode mixture layer by mixing the active material, the binder and the conductive material on the current collector, the active material including a carbon material including a plurality of pores in which crystalline and amorphous materials are mixed, The particle size (D50) of the active material is 4 탆 to 6 탆.

(Particle size (D50): particle size when the accumulated volume ratio is 50% in the curve for the cumulative particle size distribution of the active material)

The supercapacitor according to the embodiment may include an active material in the electrode, and the distribution of the particle size and the particle size of the active material may be optimized. In detail, the active material may have a D50 value of 4 to 6 占 퐉, a D10 value of 0.5 占 퐉 to 2.5 占 퐉, and a D90 value of 9 占 퐉 to 12 占 퐉 in a curve for the cumulative particle size distribution of the active material Lt; / RTI > Accordingly, the tap density and the sheet density of the active material can be improved and the electrostatic capacity of the supercapacitor can be improved.

Also, the energy density and the power density of the supercapacitor according to the embodiment can be improved. In detail, since the electrode includes an active material having an optimized particle size and a volume ratio by particle size, the density of the active material can be improved and the electrical resistance can be reduced. Accordingly, the energy density and the power density of the supercapacitor can be improved to realize high power and high capacity characteristics.

1 is an exploded perspective view schematically showing a supercapacitor according to an embodiment.
2 is a view illustrating a first electrode, a second electrode, and a separation membrane of a supercapacitor according to an embodiment.
Fig. 3 is a view schematically showing an enlarged shape of a part (region A in Fig. 2) of the active material according to the embodiment.
4 is a diagram showing the crystal structure of the crystalline region (region B in FIG. 3) in the active material according to the embodiment.
5 is an enlarged view of a portion of one of the first electrode and the second electrode according to the embodiment.
6 is a graph showing the curves of the particle size distribution of the active material according to the embodiment.
7 is a flowchart illustrating a method of manufacturing a supercapacitor according to an embodiment.
8 is a view showing a process of forming an active material by heat treatment and activation treatment in the method of manufacturing a supercapacitor according to an embodiment.

In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under / under" Quot; includes all that is formed directly or through another layer. The criteria for top / bottom or bottom / bottom of each layer are described with reference to the drawings.

Also, when a part is referred to as being "connected" to another part, it includes not only a case of being "directly connected" but also a case of being "indirectly connected" with another member in between. Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

Hereinafter, a supercapacitor according to an embodiment will be described with reference to the drawings.

FIG. 1 is an exploded perspective view schematically illustrating a supercapacitor 1000 according to an embodiment of the present invention. FIG. 2 is an exploded perspective view schematically illustrating a supercapacitor 1000 according to an embodiment of the present invention. Fig.

The supercapacitor 1000 according to the embodiment may be an electric double layer capacitor (EDLC).

1 and 2, the supercapacitor 1000 may include a first electrode 100, a second electrode 200, a separation membrane 300, and a cover case 500.

The cover case 500 may include a rigid material. In detail, the cover case 500 may include metal, glass, quartz, and the like. For example, the cover case 500 may include aluminum and may be transparent or translucent, including glass or quartz. Alternatively, the cover case 500 may include a flexible material. For example, the cover case 500 may include plastic.

Further, the cover case 500 may have a cylindrical shape. Accordingly, the cover case 500 can protect the first electrode 100, the second electrode 200, and the separator 300 accommodated therein from an external impact. However, the embodiment is not limited thereto, and the cover case 500 may include various materials, and may have various shapes.

The first electrode 100 may be disposed in the cover case 500. The first electrode 100 may include a first current collector 110 and a first electrode material mixture layer 120.

The first electrode 100 may be an anode. In this case, the first current collector 110 may be a positive electrode collector, and the first electrode material mixture layer 120 may be a positive electrode mixture layer.

The first current collector 110 may include a conductive metal. For example, the first current collector 110 may include at least one of aluminum (Al), copper (Cu), gold (Au), silver (Ag), stainless steel (STS), tantalum (Ta) Niobium (Nb), and combinations thereof. Alternatively, the first current collector 110 may include a conductive resin. For example, the first current collector 110 may include a carbon-based conductive polymer.

The first current collector 110 may be in the form of a foil. However, the embodiment is not limited thereto, and the first current collector 110 may have various shapes such as a mesh shape.

The first electrode material mixture layer 120 may be disposed on the first current collector 110. For example, the first electrode material mixture layer 120 may be disposed on at least one surface of the first current collector 110. The first electrode material mixture layer 120 may be in direct contact with the first current collector 110.

The first electrode material mixture layer 120 may include an active material 1 containing carbon. For example, the active material 1 of the first electrode material mixture layer 120 may be activated carbon. In detail, the active material 1 of the first electrode material mixture layer 120 may be porous activated carbon. The first electrode material mixture layer 120 may further include a binder 121 and a conductive material 123.

The second electrode 200 may be disposed in the cover case 500. The second electrode 200 may include a second current collector 210 and the second electrode material mixture layer 220.

The second electrode 200 may be a cathode. In this case, the second current collector 210 may be an anode current collector, and the second electrode material mixture layer 220 may be a cathode electrode mixture layer.

The second current collector 210 may include a conductive metal. For example, the second current collector 210 may be made of an alloy of aluminum (Al), gold (Au), silver (Ag), stainless steel (STS), nickel (Ni), copper (Cu) Or the like. Alternatively, the second current collector 210 may include a conductive resin. For example, the second current collector 210 may include a carbon-based conductive polymer.

In addition, the second current collector 210 may be in the form of a foil. However, the embodiment is not limited to this, and the second current collector 210 may have various shapes such as a mesh shape.

The second electrode assembly layer 220 may be disposed on the second current collector 210. For example, the second electrode assembly layer 220 may be disposed on at least one surface of the second current collector 210. The second electrode assembly layer 220 may be in direct contact with the second current collector 210.

The second electrode material mixture layer 220 may include an active material 1 containing carbon. For example, the active material 1 of the second electrode material mixture layer 220 may be activated carbon. In detail, the active material 1 of the second electrode material mixture layer 220 may be a porous activated carbon. In addition, the second electrode material mixture layer 220 may further include a binder 121 and a conductive material 123. At this time, the binder 121 and the conductive material 123 included in the second electrode material mixture layer 220 are the same as the binder material 121 and the conductive material 123 included in the first electrode material mixture layer 120 .

Wherein at least one of the first electrode 100 and the second electrode 200 includes an electrode forming composition including the active material 1, the binder 121 and the conductive material 123 on the current collector Can be rolled and formed.

Alternatively, at least one of the first electrode 100 and the second electrode 200 may include the active material 1, the binder 121, and the conductive material 123 on the current collector A composition for forming an electrode may be formed by coating.

Alternatively, at least one of the first electrode 100 and the second electrode 200 may include at least one of the above-described composition for electrode formation including the active material 1, the binder 121, and the conductive material 123 May be formed in a sheet form and attached to the current collector, followed by drying.

However, the embodiment is not limited thereto, and the first electrode 100 and / or the second electrode 200 may be formed in such a way as to satisfy the required characteristics.

The separation membrane 300 may be disposed between the first electrode 100 and the second electrode 200. The separation layer 300 may be disposed in contact with the first electrode 100 and the second electrode 200. For example, the separator 300 may be disposed in contact with the first electrode material mixture layer 120 of the first electrode 100 and the second electrode material mixture layer 220 of the second electrode 200 . One surface of the separator 300 and the other surface opposite to the one surface of the separator 300 are connected to one surface of the first electrode 100 facing the one surface and the other surface of the separator 300, As shown in FIG. For example, one surface and the other surface of the separator 300 may be formed on one surface of the first electrode material mixture layer 120 facing the one surface and the other surface of the separation material 300, And can be disposed in direct contact with one surface. The first electrode 100 and the second electrode 200 may be spaced apart from each other by the separator 300. Accordingly, it is possible to prevent a short circuit between the first electrode 100 and the second electrode 200.

The separator 300 may be formed of any one of a polyethylene nonwoven fabric, a polypropylene nonwoven fabric, a polyester nonwoven fabric, a polyacrylonitrile porous separator, a poly (vinylidene fluoride) hexafluoropropane copolymer porous separator, a cellulose porous separator, And may include at least one. However, the embodiment is not limited thereto, and the separator 300 may include a material capable of satisfying the characteristics required for the separator of the supercapacitor.

The first electrode 100, the separator 300, and the second electrode 200 may be sequentially stacked and wound. For example, the separator 300 may be laminated and wound such that the separator 300 is positioned between the first electrode 100 and the second electrode 200. That is, the first electrode 100, the separator 300, and the second electrode 200 are sequentially stacked and then formed into a roll shape. Thereafter, the first electrode 100, the separator 300, have. That is, the first electrode 100, the separator 300, and the second electrode may be received in the cover case 500 in the form of a roll.

The first electrode 100, the second electrode 200, and the separator 300 may be impregnated with an electrolytic solution.

The electrolytic solution may be one of an aqueous electrolytic solution and a non-aqueous electrolytic solution. The aqueous electrolytic solution may have excellent electrical characteristics. In detail, when the aqueous electrolytic solution is used as the electrolytic solution of the supercapacitor, the internal resistance of the supercapacitor may be reduced according to the excellent electrical conductivity characteristics of the aqueous electrolytic solution. However, when the aqueous electrolytic solution is used, the driving voltage, which is the voltage used for the supercapacitor, is low and the energy density is low.

The non-aqueous liquid electrolyte has lower electrical conductivity and higher viscosity than the aqueous electrolyte, but can be applied to a supercapacitor in a high-temperature and high-voltage environment due to a high potential difference. Accordingly, the super capacitor can be miniaturized, and the energy density and the power density of the super capacitor can be improved.

Therefore, it may be preferable to use the non-aqueous liquid electrolyte in consideration of characteristics such as high-voltage characteristics, energy density, power density, etc. of the supercapacitor 1000 according to the embodiment.

The electrolytic solution may include a solvent and an electrolyte salt.

The solvent may be an organic electrolytic solution. For example, the solvent may be selected from the group consisting of acetonitrile (ACN), propylene carbonate (PC), sulfolane (SL), adiponitrile (AND), ethylene carbonate (EC), dimethyl carbonate (DMC) ), Dimethylsulfone (DMS), ethyl methanesulfonate (EMS), gamma-butyrolactone (GBL), formamide (DMF), and dimethyl ketone (DMK). Among them, acetonitrile (ACN) or propylene carbonate (PC) is more stable than other solvents in terms of electrical and chemical stability, and is superior in characteristics to be able to realize high voltage characteristics by being applied to a supercapacitor, . However, the embodiment is not limited thereto, and the solvent of the supercapacitor 1000 may include a material capable of satisfying the required characteristics.

The solvent may comprise from about 78 vol% to about 82 vol%, based on the total volume of the electrolyte. Preferably, the solvent may comprise from about 79 vol% to about 81 vol%, based on the total volume of the electrolyte. Most preferably, the solvent may comprise from about 79.5% by volume to about 80.5% by volume of the total volume of the electrolyte.

When the volume of the solvent is less than about 78 vol% of the total volume of the electrolyte, it may be difficult to dissolve the electrolyte salt added to the electrolyte, and when the volume of the solvent exceeds about 82 vol% Electrolyte salts may be reduced and the number of dissociated cations and anions may decrease. That is, if the solvent is out of the above range, the overall capacitance of the supercapacitor 1000 may be lowered.

The electrolyte salt may be at least one selected from the group consisting of tetraethylammonium tetrafluoroborate (TEABF ₄ ), trimethylethylammonium tetrafluoroborate (TEMABF ₄ ), bipyrrolidinium tetrafluoroborate (SPBBF ₄ ), hexafluorophosphate (EMIPF ₆ ) And 1-butylpyridinium bisimide (BPTFSI).

The electrolyte salt may be dissociated into the solvent. For example, the electrolyte salt may be an electrolyte ion 30 which is dissociated into the solvent and contains a cation and an anion. In detail, the dissociated cation in the solvent may be at least one selected from TMA ⁺ , TEA ⁺ , TBA ⁺ , TMEA ⁺ , TEMA ⁺ , SBP ⁺ , EMI ⁺ and BPT ⁺ , and the anion dissociated in the solvent is BF ₄ ^- , PF ₆ ^- , TFSI ^- , FSI ^-, and CF ₃ SO ₃ ^- .

That is, the electrolytic solution may be an electrolytic solution containing a cation and an anion formed by dissociating the electrolyte salt in the solvent.

The electrolyte salt may be included in an amount of about 18% by volume to about 22% by volume based on the total volume of the electrolytic solution. Preferably, the electrolyte salt may comprise from about 19% to about 21% by volume of the total volume of the electrolyte. Most preferably, the electrolyte salt may be included in an amount of about 19.5% by volume to about 20.5% by volume based on the total volume of the electrolytic solution.

If the volume of the electrolyte salt is less than about 18 vol% of the total volume of the electrolyte, the number of cations and anions dissociated in the solvent may be less and if the volume of the electrolyte salt is greater than about 22 vol% So that some of the electrolyte salt may not dissociate into ions in the solvent.

The supercapacitor 1000 according to the embodiment may further include a separation membrane. The supercapacitor 1000 may further include an isolation layer 400 disposed between the first electrode 100 and the second electrode 200 in addition to the isolation layer 300.

The outer separator 400 may be disposed on the first electrode 100. In detail, the outer separator 400 may be disposed between the cover case 500 and the first electrode 100. The outer separator 400 may be disposed in contact with the first electrode 100. For example, one side of the outer separator 400 may be disposed in direct contact with the other side of the first electrode 100.

When the outer separator 400 is wound in the form of a roll in the cover case 500, the other surface of the outer separator 400 may be in direct contact with the other surface of the second electrode 200 have.

The first electrode 100, the second electrode 200, the separator 300 and the external separator 300 are formed on the external separator 400, the first electrode 100, the separator 300 And the second electrode 200 may be stacked in this order to form a laminated body. The laminated body may be wound in a roll form and accommodated in the cover case 500. Accordingly, the outer separator 300 may be in direct contact with the second electrode 200 as described above.

That is, the electrode assembly layer may be formed on one surface and the other surface of the first current collector 110 and the second current collector 220, respectively, by the outer separator 400. In other words, the electrode assembly layer can be formed on both sides of each current collector, so that an improved electrostatic capacity can be realized. When the first electrode 100 and the second electrode 200 are rolled up, It is possible to prevent the occurrence of a short circuit.

Also, it is possible to prevent short-circuiting between the cover case 500 and the first electrode 100 by the external separator 300.

The supercapacitor 1000 may further include a lead wire. For example, the supercapacitor 1000 may include a first lead line 600 and a second lead line 700.

The first lead line 600 may be connected to the first electrode 100. For example, the first lead 600 may be in direct contact with the first electrode 100. The second lead line 700 may be connected to the second electrode 200. For example, the second lead line 700 may be in direct contact with the second electrode 200.

The first lead wire 600 and the second lead wire 700 may extend from the inside of the cover case 500 to the outside of the cover case 500.

3 and 4, the active material 1 included in at least one of the first electrode 100 and the second electrode 200 according to the embodiment will be described in more detail.

Fig. 3 is a view schematically showing an enlarged view of a part (region A in Fig. 2) of the active material 1 according to the embodiment. Fig. 4 is a cross- B region) shown in FIG.

3 and 4, the active material 1 may be formed of a carbon material including carbon. For example, the active material 1 may be formed using a carbon material such as a petroleum pitch, a coal pitch, a green coke, a calcination coke, and a coke dust . The active material 1 formed of the carbon material may be one of activated carbon, graphite, fullerene, C60, soft carbons, carbon black, and the like. However, the embodiment is not limited to this, and may include a material capable of satisfying the characteristics required for the active material 1.

The active material 1 may include an amorphous material 10 and a crystalline material 20. The amorphous material 10 may have an irregular atomic arrangement, and the crystalline material 20 may have a crystal lattice.

The crystalline material (20) and the amorphous material (10) may be mixed in the active material (1). For example, the crystalline material 20 may be irregularly arranged in the active material 1. In the active material (1), the crystalline material (20) may be surrounded by the amorphous material (10).

The crystalline material 20 may be formed during the heat treatment of the carbon material. In detail, the crystalline material 20 may be formed by partially crystallizing the amorphous material 10 of the carbon material by the heat treatment process.

The crystalline material 20 may serve as a passage for allowing the electrolyte ions 30 to flow easily. That is, the active material (1) can lower the electrical resistance and improve the electrical conductivity by the crystalline material (20).

The amorphous material 10 may serve to store the electrolyte ions 30. In detail, the active material 1 may include an amorphous material 10 including a plurality of pores 11. The amorphous material 10 may have a specific surface area increased by the pores 11. That is, the active material 1 includes a plurality of pores 11, and the electrolyte ions 30 may be adsorbed to the amorphous material 10 through the crystalline material 20. Therefore, the active material 1 can improve the electrostatic capacity by the amorphous material 10.

The presence or absence of the crystalline material (20) in the active material (1) can be confirmed by X-ray diffraction (XRD). Diffraction occurs in a part of the crystal of the material by X-ray diffractometry when X-ray is irradiated. At this time, the angle and the intensity at which the diffraction occurs are unique to each structure of the material, and information on the kind and amount of the crystalline material contained in the sample can be grasped using the diffracted X-ray data .

The crystalline material 20 may be about 40% to about 91% of the unit weight (g) of the active material 1. If the proportion of the crystalline material 20 is less than about 40%, the proportion of the amorphous material 10 may be increased to increase the specific surface area. Accordingly, there is a problem that the electric conductivity decreases and the electrostatic capacitance of the entire supercapacitor 1000 decreases. Also, when the proportion of the crystalline material (20) is more than about 91%, the specific surface area of the active material (1) is excessively reduced and the overall capacitance is reduced.

The pores (11) of the active material (1) may have a size of about 1 nm or less. The size of the pores 11 may be an average diameter length. When the active material 1 includes a plurality of pores 11, the sizes of the pores 11 may be equal to each other. In detail, the pores 11 may have the same diameter. Alternatively, the sizes of the pores 11 may be different from each other. In detail, the pores 11 may have diameters different from each other. Alternatively, the active material 1 may include pores 11 having the same diameter and pores 11 having diameters different from each other. The specific surface area of the active material 1 may be increased by the pores 11, that is, the pores 11 included in the amorphous material 10.

The presence or absence of the pores 11 in the active material 1 may be a factor affecting the specific surface area of the active material 1. In addition, the size of the pores 11 may be a factor affecting the specific surface area. That is, the size of the pores 11 and the distribution characteristics of the pores 11 may be factors that affect the amount and / or mobility of the electrolyte ions 30 disposed in the pores 11.

Also, the pores 11 may be from about 60% to about 85% of the total volume of the amorphous material 10. If the volume of the pores 11 is less than about 60% of the total volume of the amorphous material 10, the specific surface area can be reduced and the capacitance can be reduced. Also, if the volume of the pores 11 exceeds about 85% of the total volume of the amorphous body 10, the specific surface area may be increased to deteriorate the accessibility of the electrolyte ions 30, And the overall electrical characteristics may be lowered.

The specific surface area of the active material (1) may be about 200 m ² / g to about 1200 m ² / g. When the specific surface area of the active material 1 is within the above range, the electrolytic ions 30 can easily flow into the pores 11 of the amorphous body 10 or between the lattices of the crystalline body 20, .

The pores 11 may be formed by an activation process. In detail, the pores 11 can be formed by alkali activating the heat-treated carbon material. The size and the ratio of the pores 11 formed in the active material 1 can be controlled by the alkali activation treatment.

The active material 1 according to the embodiment may include carbon. At this time, the active material 1 may include a crystalline layer 20 having a layered structure. In detail, the crystalline material 20 may have a layered structure in which carbon atoms are bonded by covalent bonds and van der Waals bonds. More specifically, the crystalline material 20 is bonded to three carbon atoms disposed at adjacent positions on the same plane in a covalent bond, and the carbon atoms are bonded to carbon atoms arranged on other planar surfaces, that is, And may have a lamellar structure bonded by a Derval's bond. The bond length (l) between the carbon atoms bonded by the covalent bond may be about 1.42 Å.

The carbon atoms bonded by the covalent bond may extend in a first direction. For example, the first direction may be the a-axis direction of the crystalline material 20. In detail, the a-axis direction may be a direction in which the (100) plane of the crystalline material 20 grows. In addition, the carbon atoms bonded by van der Waals bond may extend in a second direction. For example, the second direction may be the c-axis direction of the crystalline material 20. In detail, the c-axis direction may be a direction in which the (002) plane of the crystalline material 20 grows.

The first direction and the second direction may be different directions. In detail, the first direction and the second direction may intersect. More specifically, the first direction and the second direction may be perpendicular to each other.

The crystalline material 20 may have a layered structure as described above. At this time, if the X-ray diffraction method (XRD) is used, the distance between the layers in the layered structure, that is, the distance between the planes of the crystalline material 20, can be known. For example, the lattice spacing of the crystalline material 20 can be obtained using the Bragg equation (1) below.

&Quot; (1) " nλ = 2dsinθ

(n = reflection index,? = wavelength value of X-ray, d = distance between planes by Miller index of crystalline)

That is, it is possible to grasp the lattice spacing of the crystalline material 20 by using the data for the X-ray diffraction analysis (XRD) and the formula (1). The crystalline lattice spacing of 20 according to the embodiment (d ₀₎ may be about 0.37nm to about 0.42nm. Preferably, the lattice spacing (d ₀₎ of the crystalline (20) may be from about 0.37nm to about 0.40nm. That is, the distance between the (002) planes of the crystalline material 20 may be about 0.37 nm to about 0.42 nm.

If the lattice spacing (d ₀₎ is less than approximately 0.37nm of the crystalline (20), it may not be easy for the electrolyte ions 30 are inserted and moved between the layer and the layer of the crystalline (20). Further, if it exceeds the lattice spacing (d ₀₎ of about 0.42nm of the crystalline (20), the distance between the layer and the layer of the crystalline 20 can be distanced loss of crystallinity. That is, the van der Waals bonds between the carbon atoms may be broken and the crystallinity may be lost. As a result, there is a problem that electric conductivity or electrostatic capacity is lowered.

5 is an enlarged view of a portion of one of the first electrode 100 and the second electrode 200 according to the embodiment. For example, FIG. 5 may be an enlarged view of a portion of the first electrode 100 according to the embodiment.

The first electrode 100 may include a first electrode material mixture layer 120. The first electrode material mixture layer 120 may be disposed in direct contact with one surface of the first current collector 110. The first electrode material mixture layer 120 may be formed of an electrode forming composition including an active material 1, a binder 121, and a conductive material 123.

The binder (121) can impart adhesiveness to the electrode forming composition. For example, the binder 121 may be selected from the group consisting of carboxymethylcellulose (CMC), linear polyvinylidene fluoride (PVDF), branched polyvinylidene fluoride (PVDF), polyvinylpyrrolidone ), Styrene-butadiene rubber (SBR), polyethylene (PE), polypropylene (PP), and polyvinyl alcohol (PVA). However, the embodiment is not limited thereto and may include a material capable of satisfying the properties required for the binder.

The binder 121 may be included in an amount of about 1% by weight to about 45% by weight based on 100% by weight of the total composition for electrode formation. When the binder 121 is less than about 1% by weight based on 100% by weight of the entire electrode forming composition, the physical adhesion is reduced and the binder can not be properly used. In addition, when the binder 121 is more than about 45% by weight based on 100% by weight of the entire electrode forming composition, the content of the conductive material may decrease and the conductivity may be lowered.

The conductive material 123 may impart conductivity to the electrode forming composition. For example, the conductive material 123 may electrically connect neighboring active materials 1 to each other. In detail, the conductive material 123 may be dispersed among the active materials 1. In addition, the conductive material 123 may be disposed between the adjacent active materials 1 by the binder 121 to connect the active materials 1 to each other. That is, the conductive material 123 may serve as a bridge for connecting the active materials 1 with the binder 121.

The conductive material 123 may include a conductive material. For example, the conductive material 123 may include at least one of carbon black, graphene, carbon nanotube (CNT), and carbon nanofiber (CNF). However, the embodiment is not limited to this, and may include a material capable of satisfying the characteristics required for the conductive material.

The conductive material 123 may be included in an amount of about 1% by weight to about 45% by weight based on 100% by weight of the entire electrode forming composition. When the conductive material 123 is less than about 1% by weight based on 100% by weight of the entire electrode forming composition, the conductivity of the electrode forming composition may be lowered. Also, when the conductive material 123 is more than about 45% by weight based on 100% by weight of the entire electrode forming composition, the content of the binder may be reduced and the adhesion may be deteriorated.

The composition for electrode formation may further comprise a solvent. The solvent may be water or organic solvent. In addition, the solvent may be contained in an amount of about 10% by weight to about 97% by weight based on 100% by weight of the entire electrode-forming composition. If the solvent is out of the above-mentioned range, the adhesiveness and the conductivity may be deteriorated.

Referring to FIG. 5, the active materials 1 included in the first electrode material mixture layer 120 may be connected to each other. For example, the active materials (1) adjacent to each other may be connected by at least one conductive material (123) disposed between the active materials (1). In detail, adjacent active materials 1 may be connected to each other by the binder 121, and the active material 1 and the conductive material 123 adjacent to the active material 1 are connected to each other by the binder 121 . That is, the active materials 1 may be directly and / or indirectly connected and electrically connected by the conductive material 123 and the binder 121, and may be disposed on the first current collector 110 .

6 is a graph showing the particle size distribution curve of the active material 1 according to the embodiment. In detail, the particle size distribution curve may be a distribution curve accumulated from the smallest particle size to the largest particle size order. The particle size distribution curve can be obtained by measuring in the same manner as a sieve, a microscope, a sedimentation method, an electron-pair detection method, or laser diffraction.

In the examples, the particle size of the active material (1) was analyzed using Hydro2000S, a particle size analyzer of MALVERN. In detail, the particle size analyzer is a device using laser diffraction. The particle size is analyzed by irradiating the active material 1 with a laser and measuring an angle change according to intensity of light scattered when the laser passes through the active material 1 Equipment. Also, the particle size of the active material 1 can be analyzed through the scattering angle of the laser beam passing through the active material 1 as the particle size is smaller, and the angle of light scattering becomes smaller as the particle size is smaller . The particle size (D10), particle size (D50), and particle size (D90) values of the active material (1) can be obtained by the particle size analysis method described above. When the cumulative volume ratio of the particle size (D10), the particle size (D50), and the particle size (D90) is determined with respect to the particle size at the total volume of the active material (1) , 50%, and 90%, respectively. Here, the particle size (D50) may mean the average particle size of the active material (1).

Referring to FIG. 6, the active material 1 included in the electrode mix layer may have a particle size. For example, the particle size of the active material 1 may be about 40 탆 or less. The particle size of the active material 1 may be about 0.1 탆 to about 37 탆 in detail. More specifically, the particle size of the active material 1 may be about 0.1 탆 to about 35 탆. If the particle size of the active material 1 is greater than about 40 탆, the density of the active material contained in the electrode may be lowered and the overall capacitance may decrease. In addition, when the particle size is less than about 0.1 탆, the density of the active material contained in the electrode may be excessively high, and the electrical resistance may increase, thereby deteriorating the electrical characteristics of the electrode.

The active material 1 may have various particle sizes within the particle size range described above, and may be mixed at various volume ratios according to the particle size. For example, the active material 1 having a particle size of about 10 mu m or less may be about 95% or less of the total volume of the active material. In detail, the active material 1 having a particle size of about 10 mu m or less may be about 93% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 10 mu m or less may be about 90% or less of the total volume of the active material.

The active material 1 having a particle size of about 8 탆 or less may be about 85% or less of the total volume of the active material. In detail, the active material 1 having a particle size of about 8 mu m or less may be about 83% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 8 탆 or less may be about 80% or less of the total volume of the active material.

The active material 1 having a particle size of about 6 탆 or less may be about 65% or less of the total volume of the active material. In detail, the active material 1 having a particle size of about 6 m or less may be about 63% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 6 탆 or less may be about 60% or less of the total volume of the active material.

The active material 1 having a particle size of about 4 탆 or less may be about 40% or less of the total volume of the active material. In detail, the active material 1 having a particle size of about 4 탆 or less may be about 38% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 4 m or less may be about 35% or less of the total volume of the active material.

The active material 1 having a particle size of about 2 m or less may be about 25% or less of the total volume of the active material. In detail, the active material 1 having a particle size of about 2 m or less may be about 23% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 2 탆 or less may be about 20% or less of the total volume of the active material.

Particle Size Size (㎛) ratio (%) Less than 1.1㎛ 4.77  1.1 탆 to 2.2 탆 12.74 2.2 탆 to 3.3 탆 14.13 3.3 탆 to 4.4 탆 12.33 4.4 탆 to 5.8 탆 15.22 5.8 탆 to 7.6 탆 16.77 7.6 탆 to 10 탆 13.37 10 mu m to 13.2 mu m 6.72 13.2 탆 to 17.4 탆 2.34 17.4 mu m to 35 mu m 1.6

Table 1 shows the particle size of the active material 1 according to the embodiment using the particle size analyzer described above. Referring to Table 1, the volume ratio of the active material 1 having a particle size of less than about 1.1 탆 may be less than about 6% of the total volume of the active material. have. In detail, the active material 1 having a particle size of less than about 1.1 탆 can be about 5% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of less than about 1.1 占 퐉 may be about 4% to about 5% of the total volume of the active material.

The volume ratio of the active material 1 having a particle size of about 1.1 탆 to about 2.2 탆 may be about 14% or less with respect to the total volume of the active material. In detail, the active material 1 having a particle size of about 1.1 탆 to about 2.2 탆 may be about 13% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 1.1 탆 to about 2.2 탆 may be about 12% to about 13% of the total volume of the active material.

The volume ratio of the active material 1 having a particle size of about 2.2 占 퐉 to about 3.3 占 퐉 may be about 16% or less with respect to the total volume of the active material. In detail, the active material 1 having a particle size of about 2.2 탆 to about 3.3 탆 may be about 15% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 2.2 탆 to about 3.3 탆 may be about 14% to about 15% of the total volume of the active material.

The volume ratio of the active material 1 having a particle size of about 3.3 탆 to about 4.4 탆 may be about 14% or less with respect to the total volume of the active material. In detail, the active material 1 having a particle size of about 3.3 탆 to about 4.4 탆 may be about 13% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 3.3 탆 to about 4.4 탆 may be about 12% to about 13% of the total volume of the active material.

The volume ratio of the active material 1 having a particle size of about 4.4 占 퐉 to about 5.8 占 퐉 may be about 17% or less with respect to the total volume of the active material. In detail, the active material 1 having a particle size of about 4.4 탆 to about 5.8 탆 may be about 16% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 4.4 탆 to about 5.8 탆 may be about 15% to about 16% of the total volume of the active material.

The volume ratio of the active material 1 having a particle size of about 5.8 탆 to about 7.6 탆 may be about 18% or less with respect to the total volume of the active material. In detail, the active material 1 having a particle size of about 5.8 탆 to about 7.6 탆 can be about 17% or less with respect to the total volume of the active material. More specifically, the active material 1 having a particle size of about 5.8 탆 to about 7.6 탆 may be about 16% to about 17% of the total volume of the active material.

The volume ratio of the active material 1 having a particle size of about 7.6 탆 to about 10 탆 may be about 15% or less with respect to the total volume of the active material. In detail, the active material 1 having a particle size of about 7.6 탆 to about 10 탆 can be about 14% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 7.6 탆 to about 10 탆 may be about 13% to about 14% of the total volume of the active material.

The volume ratio of the active material 1 having a particle size of about 10 mu m to about 13.2 mu m may be about 8% or less with respect to the total volume of the active material. In detail, the active material 1 having a particle size of about 10 탆 to about 13.2 탆 can be about 7% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 10 탆 to about 13.2 탆 may be about 6% to about 7% of the total volume of the active material.

The volume ratio of the active material 1 having a particle size of about 13.2 탆 to about 17.4 탆 may be about 4% or less with respect to the total volume of the active material. In detail, the active material 1 having a particle size of about 13.2 탆 to about 17.4 탆 can be about 3% or less with respect to the total volume of the active material. More specifically, the active material 1 having a particle size of about 13.2 탆 to about 17.4 탆 may be about 2% to about 3% of the total volume of the active material.

The volume ratio of the active material 1 having a particle size of about 17.4 탆 to about 35 탆 may be about 3% or less with respect to the total volume of the active material. In detail, the active material 1 having a particle size of about 17.4 탆 to about 35 탆 can be about 2% or less of the total volume of the active material. More specifically, the active material 1 having a particle size of about 17.4 占 퐉 to about 35 占 퐉 may be about 1% to about 2% of the total volume of the active material.

Referring to the particle size distribution curve of the active material 1, the active material 1 may have a particle size D10, a particle size D50, and a particle size D90.

The average particle size (D50) of the active material (1) may be about 4 탆 to about 6 탆. In detail, the average particle size (D50) of the active material 1 may be about 4.5 탆 to about 5.5 탆. More specifically, the average particle size (D50) of the active material 1 may be about 4.7 占 퐉 to about 5.3 占 퐉. If the average particle size D50 of the active material 1 is out of the range described above, the tap density of the active material 1 may be reduced, The sheet density of the sheet can also be reduced. Thus, the electrical resistance of the electrode can be increased and the overall capacitance of the supercapacitor can be reduced.

The particle size D10 of the active material 1 may be about 0.5 탆 to about 2.5 탆. In detail, the particle size D10 of the active material 1 may be about 1 탆 to about 2 탆. More specifically, the particle size D10 of the active material 1 may be about 1.3 탆 to about 1.7 탆.

The particle size D90 of the active material 1 may be about 9 탆 to about 12 탆. In detail, the particle size D90 of the active material 1 may be about 9.5 탆 to about 11 탆. More specifically, the particle size D90 of the active material 1 may be about 9.5 占 퐉 to about 10.5 占 퐉. The value of the average particle size D50 may be increased or decreased when the particle size D10 and the particle size D90 of the active material are out of the range described above and thus the tap density of the active material 1, The sheet density may vary.

That is, when the values of the particle size (D10), the particle size (D50), and the particle size (D90) of the active material satisfy the above-described range, the electrostatic capacity of the super capacitor can be effectively improved and the internal electrical resistance can be reduced, It is possible to maximize the improvement of the overall electrical characteristics of the capacitor.

Although the supercapacitor 1000 according to the embodiment is an electric double layer capacitor (EDLC), the embodiments are not limited thereto. The first electrode 100 and the second electrode 200 impregnated in the electrolytic solution And may be a hybrid capacitor which is an asymmetric electrode. For example, in the supercapacitor 1000, one of the first electrode 100 and the second electrode 200 may include a high-capacity material including the above-described active material 1, A high output characteristic can be realized by including an oxide instead of the active material (1). That is, when the supercapacitor 1000 is a hybrid capacitor, the electrode including the active material 1 may include the active material 1 having the above-described particle size. Accordingly, the electrical resistance of the supercapacitor can be reduced, the capacitance can be improved, and the overall energy density and power density of the supercapacitor can be improved.

FIG. 7 is a flowchart illustrating a method of manufacturing a super capacitor according to an embodiment, and FIG. 8 is a view illustrating a process of forming an active material by heat treatment and activation treatment in a method of manufacturing a super capacitor according to an embodiment.

Referring to FIGS. 7 and 8, a method of manufacturing a supercapacitor 1000 according to an embodiment may include a step of preparing a carbon material, a heat treatment step, an activation treatment step, an electrode forming step, and a cell forming step.

The step of preparing the carbon material may be a step of preparing a carbon material for forming the active material (1). For example, the carbon material may be a petroleum pitch, a coal pitch, a green coke, a calcination coke and a coke dust.

Subsequently, the carbon material may be heat-treated to form the active material (1). The heat treatment step may be a step of forming the crystalline material 20 and the amorphous material 10 in the active material 1.

The heat treatment step may be performed in an inert gas atmosphere. For example, the heat treatment step may be performed in a helium, argon, nitrogen atmosphere, or the like. However, the embodiment is not limited to this and can be carried out in an atmosphere capable of satisfying the characteristics required in the heat treatment.

The heat treatment step may be heat treated at a temperature of about 650 ° C to about 900 ° C. When the heat treatment temperature is less than about 650 ° C, the crystalline material 20 may not be formed in the active material 1. In addition, when the heat treatment temperature is higher than about 900 캜, the proportion of the crystalline material 20 formed in the active material 1 may be excessively high. That is, the ratio of the crystalline material 20 to the unit weight g of the active material 1 varies depending on the heat treatment temperature, and the ratio of the crystalline material 20 affects the specific surface area of the active material 1 The capacitance value can be changed. In detail, the lower the annealing temperature is, the more the proportion of the crystalline material 20 decreases and the ratio of the amorphous material 10 increases. Accordingly, the specific surface area of the active material 1 is increased, and the electrostatic capacity can be improved. Also, the higher the temperature of the heat treatment, the more the proportion of the crystalline material 20 increases and the proportion of the amorphous material 10 decreases. Accordingly, the electrical conductivity of the active material 1 can be improved, but the electrostatic capacity can be reduced.

That is, in the heat treatment step according to the embodiment, the carbon material may be heat-treated at a temperature of about 650 ° C. to about 900 ° C. to optimize the ratio of the crystalline material 20 and the amorphous material 10 in the active material 1. When the heat treatment temperature is within the above range, the crystalline material 20 may be about 40% to about 91% of the unit weight (g) of the active material 1.

Subsequently, a step of activating the active material 1 may be performed. The activation step may be a step of controlling the size and the ratio of the pores 11 of the active material. In detail, in the activation process, the amorphous material 10 is broken and the pores 11 may be formed in the amorphous material 10. In addition, the activation step may control the lattice spacing of the crystalline material 20. In detail, the activation step may adjust the distance between the (002) planes of the crystalline material 20. Accordingly, the specific surface area of the active material 1 can be increased.

The activation treatment step may be a step of activating the active material 1 using an activator containing an alkali. That is, the activation treatment step may be an alkali activation treatment step. The alkali may be lithium (Li), sodium (Na), potassium (K) metal, and the like. At this time, the active material (1) and the activator may be mixed in a weight ratio of about 1: 0.8 to about 1: 5.5. When the weight ratio of the active material (1) and the activator is less than about 1: 0.8, the active material (1) can not be sufficiently activated. Accordingly, even when the crystalline material 20 is present in the active material 1, a lattice spacing at which the electrolyte ions 30 can move can not be ensured. Further, when the weight ratio of the active material (1) and the activator exceeds about 1: 5.5, the lattice spacing of the crystalline material (20) may become excessively large. That is, the distance between the carbon atoms bonded by the van der Waals bond may be increased and the van der Waals bond may be broken. Accordingly, the crystalline material 20 may lose crystallinity. It is also preferred that the active material has a size of less than about 1 nm and is between about 60% and about 85% of the total volume of the amorphous (10) when the weight ratio of the active material (1) and the activator is out of the range of about 1: 0.8 to about 1: It may be difficult to realize the pores 11 occupying 100%. That is, it may be difficult to control the size and / or the ratio of the pores 11. As a result, the overall electrical characteristics of the active material 1 may be deteriorated.

The specific surface area of the active material (1) may be 200 m ² / g to 1200 m ² / g. When the specific surface area of the active material 1 is within the above-mentioned range, the electrolytic ions 30 can easily flow into the crystal lattices or into the pores 11 of the amorphous body 10, so that the electrostatic capacity can be improved.

The activation treatment step may proceed in an inert gas atmosphere. The inert gas may be helium, argon, nitrogen, or the like. However, the embodiment is not limited thereto, and the activation process can proceed in an atmosphere capable of satisfying the required characteristics.

The activation treatment step may be heat treated at a temperature of about 700 < 0 > C to about 1000 < 0 > C. When the activation treatment temperature is less than about 700 캜 or more than about 1000 캜, the lattice spacing of the crystalline material 20 of the active material 1 may be less than about 0.37 nm or more than about 0.42 nm. Accordingly, a path through which the electrolyte ions 30 can move is not formed, so that the electrical conductivity and the electrostatic capacity of the supercapacitor 1000 can be reduced.

The pore 11 may have a size of about 1 nm or less as the activation process is performed at a temperature of about 700 ° C. to about 1000 ° C. and the pores 11 may have a volume of about the entire volume of the amorphous material 10 From about 60% to about 85%. However, when the activation treatment temperature is out of the above range, it may be difficult to control the size and / or the ratio of the pores 11. Accordingly, the electrical characteristics of the supercapacitor 1000 may be deteriorated.

Then, the neutralization step, the washing step and the rolling step may be further carried out.

The neutralization step may proceed after the activation processing step. The neutralization step may be a step of neutralizing to remove the alkali-containing material used in the activation treatment step. The neutralization step may use hydrochloric acid, nitric acid, or the like.

The cleaning step may be performed after the neutralization step. The cleaning step may be a step of cleaning the active material (1). The cleaning step may use distilled water.

After the cleaning step, the drying step may be performed. The active material (1) may be dried by the drying step.

After the drying step, the pulverization step and the sizing step may be further performed.

The pulverizing step may be a step of pulverizing the produced active material (1). In detail, the crushing step may be a step of crushing the active material (1) so that the particle size of the active material (1) is about 40 탆 or less. For example, the pulverizing step may be a step of pulverizing the active material (1) using a super-fine pulverizer. The ultra-fine pulverizer may be one of a pulverizer such as a jet mill, a vibration mill, a colloid mill, and a disk attrition mill.

The milling step may be conducted for about 30 minutes to about 90 minutes. In detail, the milling step may be carried out for about 45 minutes to about 75 minutes. If the duration of the pulverization step is less than about 30 minutes, the particle size of the active material 1 may exceed about 40 탆, and the active material 1 may not be uniformly pulverized. Accordingly, the average particle size (D50) value of the active material () can be increased. Further, when the progressing time of the pulverizing step is more than about 90 minutes, the average particle size (D50) of the active material (1) may be reduced. For example, the average particle size (D50) of the active material 1 may be less than about 4 탆.

The sizing step may be a step of sieving the active material (1) through the pulverizing step. For example, the sizing step may be such that the particle size of the pulverized active material 1 is about 40 μm or less. The sizing step may use a squeezing apparatus having a mesh size of about 40 μm or less. In detail, in the above-mentioned spreading step, a sieving apparatus having a sieving size of about 35 mu m or less can be used.

The active material 1 that has been subjected to the seeding step may have a particle size in the range described above. That is, the active material (1) having an average particle size (D50) value of about 4 μm to about 6 μm can be obtained by the above-mentioned sizing step, and the particle size (D10) value is about 0.5 μm to about 2.5 μm, To obtain an active material (1) having a thickness of about 9 탆 to about 12 탆. The particle size of the active material 1 can be confirmed by the particle size analysis method described above.

Accordingly, the active material 1 may have a tap density in the range of about 0.3 g / mL to about 0.65 g / mL, and if the tap density is within the above-mentioned range, the electrostatic capacity of the active material 1 may increase have.

And then the electrode forming step can be carried out. The electrode forming step may be a step of forming the first electrode 100 and / or the second electrode 200 of the supercapacitor 1000 described above. The electrode forming step may include forming the first electrode material mixture layer 120 and / or the second electrode material mixture layer 220 by mixing the active material 1, the binder 121, the conductive material 123, Lt; / RTI > The first electrode material mixture layer 120 may be disposed on the first current collector 110 to serve as an anode or a cathode and the second electrode material mixture layer 220 may be disposed on the second current collector It can serve as a cathode or an anode.

In the electrode formation step, the first electrode material mixture layer 120 and the second electrode material mixture layer 220 are pressed at a constant pressure to improve the density of the electrodes, and are then adhered onto the respective current collectors 110 and 210 And the adhesion between the electrode assembly layer and the current collector can be improved through additional steps such as heating and drying.

Accordingly, the sheet density of the electrode according to the embodiment may be about 0.6 g / mL to about 1 g / mL. Here, the sheet density may mean the mixture density, and if the mixture density is within the above-mentioned range, the resistance of the electrode can be reduced, the electrostatic capacity can be improved, and the energy density and the power density can be increased.

The cell formation step can then proceed. The cell forming step may include impregnating the first electrode 100, the separator 300, the second electrode 200, and the like with an electrolyte. That is, the electrolyte may be dissociated between the first electrode 100 and the second electrode 200 to form a cell of the supercapacitor.

At this time, the first electrode 100, the separator 300, and the second electrode 200 may be sequentially stacked and wound. In detail, the first electrode 100, the separator 300, and the second electrode 200 may be formed into a roll shape and then maintained in shape through an adhesive member disposed around the roll. Accordingly, the first electrode 100, the separator 300, and the second electrode 200 can be received in the cover case 500 in the form of a roll.

However, the embodiment is not limited thereto, and may be in the form of a stack in which the separator 300 is disposed between the first electrode 100 and the second electrode.

Then, a lead wire can be formed. The lead wire may include a first lead wire 600 and a second lead wire 700. The first lead line 600 may be connected to the first electrode 100 and the second lead line 700 may be connected to the second electrode 200. At this time, the first lead 600 and the second lead 700 may extend outward from the inside of the cover case 500.

The operation and effect of the present invention will be described in more detail with reference to the following examples and comparative examples.

Example

The residue oil from the NCC (Naphta Cracking Center) process was heat treated to prepare a carbon material. The carbon material was heat-treated in an argon (Ar) atmosphere at a temperature of 750 캜 for 6 hours at a hot spot of 60 Φ * 120 cm. Subsequently, the carbon material was mixed with a KOH activator at a ratio of 1: 3, and the mixture was activated at a temperature of 700 ° C. for 2 hours in an argon (Ar) atmosphere to obtain a crystalline material having a crystalline content of 40% To 91%.

The prepared active material was pulverized at a room temperature for 60 minutes using a jet mill, and the pulverized active material was subjected to a sieving treatment using a sieving apparatus having a sieve size of 35 탆. The particle size of the active material subjected to the sieving treatment was analyzed using a particle size analyzer (Hydro2000S, manufactured by MALVERN), and a curve for the particle size distribution was obtained based on the analysis data.

Subsequently, 90 wt% of the active material, 5 wt% of the binder and 5 wt% of the conductive material were mixed to prepare a composition for electrode formation, and the electrode forming composition was pressed on the current collector of the aluminum foil by a roller to form a sheet Followed by drying to prepare an electrode.

The prepared electrode and separator were inserted into a circular cover case, and an electrolytic solution containing acetonitrile (ACN) and tetraethylammonium (TEABF ₄ ) was injected so as to impregnate the electrode and the separator, etc. to prepare a coin cell supercapacitor .

Comparative Example

The active material was prepared in the same manner as in the examples, and the step of crushing the prepared active material and the step of performing the spreading treatment were omitted, and the particle size of the active material was analyzed in the same manner as in Example to obtain a curve for the particle size distribution. Was prepared.

Then, the particle size distribution of the active material contained in each of the Examples and Comparative Examples was measured.

Particle size (D10) (占 퐉) Particle size (D50) (占 퐉) Particle size (D90) (占 퐉) Example 1.552 4.903 10.190 Comparative Example 2.993 7.130 12.879

Referring to Table 2, it can be seen that the average particle size (D50) value of the active material according to the embodiment is 6 탆 or less, while the average particle size (D50) value of the active material according to the comparative example exceeds 6 탆.

It is also understood that the particle size (D10), particle size (D50), and particle size (D90) values of the active material according to the embodiment are smaller than those of the active material according to the comparative example. That is, in the case of the embodiment, it can be seen that the active material has a particle size smaller than that of the comparative example through the pulverization step and the seeding step.

Tap density (g / mL) of active material Sheet density (g / mL) Equivalent Series Resistance (ESR _dc ) (mΩ) Capacitance (F / cc) Example 0.371 0.75 14-16 21-24 Comparative Example 0.265 0.5 20 18

Referring to Table 3, the average particle size (D50) value of the active material according to the embodiment is about 4 占 퐉 to about 6 占 퐉, the particle size D10 value is about 0.5 占 퐉 to about 2.5 占 퐉, 9 占 퐉 to about 12 占 퐉, it can be seen that the embodiment has different tap densities, sheet densities, equivalent series resistances, and electrostatic capacitance values from the comparative example.

In detail, it can be seen that the tap density of the active material according to the embodiment is about 1.4 times larger than the tap density of the active material according to the comparative example, and that the sheet density of the embodiment is about 1.5 times larger than the sheet density of the comparative example. In addition, it can be seen that the equivalent series resistance of the embodiment is about 1.25 times to 1.43 times smaller than the equivalent series of the comparative example. As a result, the electrostatic capacity of the supercapacitor according to the embodiment is about 1.16 times to about 1.33 times.

That is, the supercapacitor 1000 according to the embodiment may include the active material 1 that optimizes the volume ratio by size and size. Accordingly, the tap density and the sheet density of the active material can be maximized and the overall electrostatic capacity of the supercapacitor 1000 can be improved.

Also, in the super capacitor 1000 according to the embodiment, the internal electrical resistance can be reduced and the capacitance can be improved by the active material 1, thereby improving the energy density and power density of the supercapacitor 1000 .

The features, structures, effects and the like described in the foregoing embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

Claims (5)

A first electrode;
A second electrode spaced apart from the first electrode;
A separation membrane disposed between the first electrode and the second electrode; And
And an electrolytic solution impregnating the first electrode, the second electrode, and the separator,
Wherein at least one of the first electrode and the second electrode includes an electrode mixture layer containing an active material,
Wherein the active material comprises a carbon material including a plurality of pores in which crystalline and amorphous materials are mixed,
And the particle size (D50) of the active material is 4 to 6 占 퐉.
(Particle size (D50): particle size when the accumulated volume ratio is 50% in the curve for the cumulative particle size distribution of the active material) The method according to claim 1,
The particle size D10 of the active material is 0.5 to 2.5 占 퐉, and the particle size D90 of the active material is 9 to 12 占 퐉.
(Particle size (D10), particle size (D90): particle size when the cumulative volume ratios in the cumulative particle size distribution of the active material are 10% and 90%, respectively) The method according to claim 1,
Wherein the active material having a particle size of 2 mu m or less is 25% or less of the total volume of the active material. Preparing a carbon material;
Heat treating the carbon material;
Subjecting the heat-treated carbon material to an activation treatment to form an active material; And
Electrode forming step,
The electrode forming step is a step of forming an electrode mixture layer by mixing the active material, the binder and the conductive material on the current collector,
Wherein the active material comprises a carbon material including a plurality of pores in which crystalline and amorphous materials are mixed,
Wherein a particle size (D50) of the active material is 4 占 퐉 to 6 占 퐉.
(Particle size (D50): particle size when the accumulated volume ratio is 50% in the curve for the cumulative particle size distribution of the active material) 5. The method of claim 4,
Wherein the step of forming the active material further comprises a crushing step and a sieving step.

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