KR102066998B1 - Sodium hybrid capacitor and preparation method thereof - Google Patents

Abstract

The present invention relates to a sodium hybrid capacitor and a method of manufacturing the same, the sodium hybrid capacitor according to an embodiment of the present invention, the positive electrode including a positive electrode active material; A negative electrode including a negative electrode active material; And an electrolyte which mediates the insertion and desorption of ions between the cathode active material and the anode active material, wherein the cathode active material includes graphene, and the anode active material comprises graphene.

Description

SODIUM HYBRID CAPACITOR AND PREPARATION METHOD THEREOF

The present invention relates to a sodium hybrid capacitor and a method of manufacturing the same. Embodiments of the present invention include a novel sodium hybrid capacitor and a method of manufacturing the same, which improves electrical conductivity and energy by using a cathode active material including a sodium compound and graphene and a cathode active material including a graphene nanosheet layer.

As energy demand has increased, interest in energy storage devices has increased as a means of delivering the required energy. Energy storage devices range from portable electronic devices to large electric vehicles and smart grid technologies.

Although secondary batteries having high energy density and high capacity are widely used at present, development of electric double layer capacitors (EDLCs) and hybrid capacitors has been actively performed as an electric energy device having a higher energy density than conventional secondary batteries.

The electric double layer capacitor accumulates electric energy by using charge accumulated in the electric double layer generated at the interface between the solid electrode and the electrolyte. This is characterized by the charging and discharging reaction occurs only in the electric double layer of the electrode and the electrolyte, and because the reaction is limited to the electric double layer, the energy density stored is low as 1 ~ 10Wh / kg.

Hybrid capacitors (HCs) have been developed to improve the energy density of such low electric double layer capacitors. Hybrid capacitors have two mechanisms simultaneously: i) intercalation / deintercalation of cations and ii) adsorption / desorption of anions. . Looking at the reaction mechanism of the hybrid capacitor using the lithium-doped carbon-based material, during charging, the negative ions are adsorbed from the cathode to the carbon-based material of the anode, and the carbon-based material of the anode has a negative charge and lithium ions are the carbon of the cathode. When the battery is inserted into the system material and discharged, the lithium ions inserted into the carbon material of the negative electrode are detached and the negative ions are adsorbed to the positive electrode. Through this mechanism, the lithium hybrid capacitor can significantly lower the potential of the cathode, and the cell voltage can realize a high voltage of 3.8 V or more, which is significantly improved compared to the 2.5 V of the conventional electric double layer capacitor, and can express high energy density.

However, lithium used in conventional hybrid capacitors is expensive and the natural light source is limited. As a substitute for lithium, sodium, which has almost the same energy density as the lithium in the energy storage system, has emerged as a substitute. However, sodium in intercalation electrodes is not as easy to insert as lithium. In addition, various sodium metal oxides have been studied as positive electrode active materials, but the mobility of sodium in the oxide matrix is lower than that of lithium in lithium oxide, and it is used in hybrid capacitors because the transition metal is rapidly lost and lattice deformation occurs during sodium insertion. There is a problem.

In the case of electrodes in which adsorption and desorption takes place, porous carbon having a large surface area has been widely used. In particular, activated carbon is widely used, but due to the low electrical conductivity of porous carbon, it has not yet reached a satisfactory level in power density.

10-1783435

It is an object of the present invention to provide a novel sodium hybrid capacitor and a method of manufacturing the same having improved electrical conductivity, energy density and durability.

Sodium hybrid capacitor according to an embodiment of the present invention, the positive electrode including a positive electrode active material; A negative electrode including a negative electrode active material; And an electrolyte which mediates the insertion and desorption of ions between the cathode active material and the anode active material, wherein the cathode active material includes a sodium compound and graphene, and the anode active material includes graphene.

The sodium compound may include a material represented by Formula 1 below.

[Formula 1] NaxMy (PO ₄ ) z

(Transition metal M is one or two or more metal elements selected from V, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Sn, Sb, Bi, Ta and W, 0 <x≤4, 0 <y≤3, 1≤z≤3)

The sodium compound may include NaTi ₂ (PO ₄ ) ₃ .

Graphene included in the negative electrode active material may be a graphene nanosheet layer.

The negative electrode may include a negative electrode current collector having the negative electrode active material disposed on one surface thereof, and the negative electrode active material may be oriented in a vertical direction with respect to one surface of the negative electrode current collector.

Method for manufacturing a sodium hybrid capacitor according to an embodiment of the present invention, preparing a positive electrode coated with a positive electrode active material on one surface of the current collector; Preparing a negative electrode having a negative electrode active material coated on one surface of a current collector; And disposing the positive electrode and the negative electrode such that an electrolyte which mediates the insertion and desorption of ions between the positive electrode and the negative electrode is disposed, wherein the positive electrode active material includes a sodium compound and graphene, and the negative electrode active material is It includes a pin.

The sodium hybrid capacitor according to the embodiment of the present invention may enable high energy density by allowing sodium ions to be easily inserted into the electrode. In addition, the graphene of the positive electrode active material may improve the mobility of sodium ions to increase the electrical conductivity. In addition, it maintains stability even after the charge and discharge cycle, and maintains high electrical conductivity and high energy density.

1 is a schematic diagram of an operating mechanism of a sodium hybrid capacitor.
2 is a result of measuring the XRD pattern of the positive electrode active material including NaTi ₂ (PO ₄ ) ₃ and graphene prepared in an embodiment of the present invention.
3 is a result of measuring the Raman spectrum of the positive electrode active material including NaTi ₂ (PO ₄ ) ₃ and graphene prepared in the embodiment prepared in the embodiment of the present invention.
4 is a result of measuring the TEM image of the anodized material including NaTi ₂ (PO ₄ ) ₃ and graphene prepared in an embodiment of the present invention.
5 is a result of measuring the XRD pattern of the graphene nanosheet layer as a negative electrode active material prepared in an embodiment of the present invention.
6 is a result of measuring the Raman spectrum of the graphene nanosheet layer as a negative electrode active material prepared in an embodiment of the present invention.
7 is a result of measuring the TEM image of the graphene nanosheet layer as a negative electrode active material prepared in an embodiment of the present invention
8 is a graph showing the charge and discharge curve of the sodium hybrid capacitor prepared in the embodiment of the present invention.
9 is a graph showing the life characteristics of the sodium hybrid capacitor manufactured in the embodiment of the present invention.
10 is a result of measuring the energy and power density of the sodium hybrid capacitor manufactured in the embodiment of the present invention.
FIG. 11 is a Ragone plot graph illustrating the energy and power densities of sodium hybrid capacitors prepared according to an exemplary embodiment of the present invention.
12 is a Nyquist plot graph comparing before and after the charge and discharge cycle of the sodium hybrid capacitor prepared in the embodiment of the present invention.
13 is a result of measuring the XRD pattern of the positive electrode active material including NaTi ₂ (PO ₄ ) ₃ and graphene after the charge and discharge cycle of the sodium hybrid capacitor prepared in the embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the following examples. Since these examples are only for illustrating the present invention, the scope of the present invention is not to be construed as being limited by these examples.

salt hybrid  Capacitor

1 is a schematic of the mechanism of action of a sodium hybrid capacitor. 1, a sodium hybrid capacitor according to an embodiment of the present invention, a positive electrode including a positive electrode active material; A negative electrode including a negative electrode active material; And an electrolyte which mediates the insertion and desorption of ions between the cathode active material and the anode active material, wherein the cathode active material includes a sodium compound and graphene, and the anode active material includes graphene.

The positive electrode may include a current collector and a positive electrode active material disposed on the current collector. The positive electrode active material included in the positive electrode should be capable of reversible intercalation and deintercalation with sodium ions, and should have excellent electrochemical performance and stability when used as a positive electrode active material for sodium hybrid capacitors. . The cathode active material of the sodium hybrid capacitor according to the embodiment of the present invention may improve the electrical conductivity by including graphene. More specifically, by applying the graphene-coated sodium sulfide to an intercalation electrode where sodium ions are inserted / desorbed, adsorption reaction of ions occurs quickly and high energy can be delivered.

The cathode active material may include a sodium compound and graphene represented by the following Chemical Formula 1.

[Formula 1] NaxMy (PO ₄ ) z

At this time, M may be a transition metal. More specifically, M is one or two or more metal elements selected from V, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Sn, Sb, Bi, Ta, and W. , 0 <x ≦ 4, 0 <y ≦ 3, and 1 ≦ z ≦ 3.

In an embodiment of the present invention, the sodium compound represented by Formula 1 may be NaTi ₂ (PO ₄ ) ₃ . It shows that it has a rhombohedral crystal structure. TiO ₆ of NaTi ₂ (PO ₄ ) ₃ is an octahedral structure, and PO ₄ is a tetrahedral structure, thus providing an internal space in which sodium ions can be dispersed. This structure allows sodium ions to move quickly inside the crystal and to have high conductivity.

The graphene may be dispersed and disposed together with the sodium compound, and may be disposed between the sodium compounds represented by Chemical Formula 1.

The graphene may be prepared by mechanical peeling, chemical vapor deposition, epitaxial synthesis and chemical peeling, and may be in the form of dots and sheets. In an embodiment of the present invention, the positive electrode active material may be prepared by a solution process of immersing a sodium compound in a solution containing graphene, or may be prepared by mixing and stirring the sodium compound and graphene.

When the cathode active material contains graphene, the graphene is connected between each NaTi ₂ (PO ₄ ) ₃ particle, which has a NASICON crystal structure. This results in very high ion conductivity and improves the performance of the hybrid capacitor.

The positive electrode is a positive electrode active material containing sodium compound and graphene, and additives Ketjen black and binder (Teflonized acetylene black) in a weight ratio of 80:10:10, and then a stainless steel mesh (area 200 mm) and dried in vacuo at 160 ° C. for 4 hours.

The binder induces excellent bonding between the active materials and serves to allow the active materials to adhere well to the current collector. The binder is polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinylchloride, polyvinyl fluoride, ethylene oxide polymer, polyvinylpyrrolidone, Polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon and the like can be used, but the present invention is limited thereto. It is not.

The stainless steel is used as a current collector and aluminum may also be used. The present invention is not limited thereto.

The negative electrode active material includes graphene.

The graphene may be prepared by mechanical peeling, chemical vapor deposition, epitaxial synthesis and chemical peeling, the graphene may be prepared by mechanical peeling, chemical vapor deposition, epitaxial synthesis and chemical peeling have. The graphene may be in the form of dots and sheets, more preferably graphene nanosheets, and may be formed in the shape of a nanosheet layer formed by gathering the nanosheets.

The graphene may be disposed on one surface of the current collector, and may be disposed to be oriented in a direction perpendicular to one surface of the current collector. Through this arrangement, the charge and discharge efficiency may be improved by securing a movement path of the ions included in the electrolyte.

The method of aligning the graphene in a vertical direction on the current collector, by preparing a negative active material in a constant magnetic field, the graphene is oriented in one direction, in particular in the direction perpendicular to one surface of the current collector according to the magnetic direction of the magnetic field It may be prepared by making it (self-orientation method). However, the manufacturing method of the graphene in the present invention is not particularly limited.

The negative electrode may include a current collector and the negative electrode active material disposed on the current collector.

At this time, a binder may be used, which induces excellent bonding between the active materials and serves to allow the active materials to adhere well to the current collector. The binder is polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinylchloride, polyvinyl fluoride, ethylene oxide polymer, polyvinylpyrrolidone, Polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon and the like can be used, but the present invention is limited thereto. It is not.

The stainless steel is used as a current collector and aluminum may also be used. The present invention is not limited thereto.

Next, the electrolyte is prepared. According to an embodiment of the present invention, it may contain sodium salt, any of those that can be used as sodium salt in the art can be used. The electrolyte may be a solid, in which case any one can be used as long as it can be used as a solid electrolyte in the art. The solid electrolyte may be formed on the negative electrode by sputtering or the like. The electrolyte may further include a non-carbonate organic solvent. The bicarbonate organic solvent may be used as long as it can be used as an organic solvent in the art. For example, benzonitrile, acetonitrile, tetrahydrofuran, 2-methyltetrahydrofuran, γ-butyrolactone, dioxolane, 4-methyldioxolane, N, N-dimethylformamide, N, N- Dimethylacetamide, N, N-dimethylsulfoxide, dioxane, 1,2-dimethoxyethane, sulfolane, dichloroethane, chlorobenzene, nitrobenzene, diethylene glycol, dimethyl ether or a mixture thereof.

According to an embodiment of the present invention, 1 M NaClO ₄ (in ethylene carbonate (EC) / dimethyl carbonate (DMC) (1: 1, v / v)) may be used as an electrolyte.

The separator is to separate the cathode and the anode and to provide a passage for sodium ions. The separator may be used that is low resistance to the ion migration of the electrolyte and excellent in the ability to hydrate the electrolyte. The separator may be in the form of a nonwoven or woven fabric comprising one selected from glass fiber, polyester, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), or a combination thereof. In addition, a coated separator including a ceramic component or a polymer material may be used to secure heat resistance or mechanical strength, and may be optionally used as a single layer or a multilayer structure. The separator is capable of ion transfer between the cathode and the anode to allow oxidation and reduction reactions to occur.

salt hybrid  Manufacturing method of capacitor

Method for manufacturing a sodium hybrid capacitor according to an embodiment of the present invention, preparing a positive electrode coated with a positive electrode active material on one surface of the current collector; Preparing a negative electrode having a negative electrode active material coated on one surface of a current collector; And disposing the positive electrode and the negative electrode such that an electrolyte which mediates the insertion and desorption of ions between the positive electrode and the negative electrode is disposed, wherein the positive electrode active material includes a sodium compound and graphene, and the negative electrode active material is It includes a pin.

The sodium compound included in the cathode active material may be a material represented by the following Chemical Formula 1, and preferably, the sodium compound may include NaTi ₂ (PO ₄ ) ₃ .

[Formula 1] Na _x M _y (PO ₄ ) _z

(Transition metal M is one or two or more metal elements selected from V, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Sn, Sb, Bi, Ta and W, 0 <x ≦ 4, 0 <y ≦ 3, 1 ≦ z ≦ 3).

In addition, the details of the positive electrode, the positive electrode active material, the negative electrode, the negative electrode active material and the electrolyte are as described above.

Example

<Example 1> NaTi ₂ (PO ₄ ) ₃ Wow Graphene  Containing Of positive electrode active material  Produce

Graphene oxide solution was prepared from natural graphite flakes by the modified Hummer Method. This water-soluble graphene oxide dispersion solution was used for the production of NaTi ₂ (PO ₄ ) ₃ surrounded by graphene. NaTi ₂ (PO ₄ ) ₃ The manufacturing method is as follows. Graphene oxide was dispersed by sonication in a mixture of distilled water and ethanol for 1 hour. Next, titanyl hydroxide is formed by adding Ti (C ₄ H ₉ O) of appropriate stoichiometric ratio with constant stirring, and then adding nitric acid solution to convert titanyl hydroxide to titanyl nitrate (titanyl nitrate). Ti (NO ₃ ) ₂ ). Appropriate stoichiometric ratios of Na ₂ CO ₃ and NH ₄ H ₂ PO ₄ were then added to the solution and sonicated for uniform mixing, then the solvent was evaporated and the mixture dried to give a gelled precursor. Finally, the precursor was pulverized well and heat treated at 350 ° C. for 3 hours, and then finally calcined at 700 ° C. for 10 hours in argon atmosphere.

Experimental Example 1 XRD  Measure

The XRD pattern of the cathode active material including NaTi ₂ (PO ₄ ) ₃ and graphene prepared in Example 1 was analyzed and the results are shown in FIG. 2.

This is consistent with the results of ICSD: 01-084-2009 and shows that it has a rhombohedral crystal structure. TiO ₆ of NaTi ₂ (PO ₄ ) ₃ is an octahedral structure, and PO ₄ is a tetrahedral structure, thus providing an internal space in which sodium ions can be dispersed. This structure allows sodium ions to move quickly inside the crystal and to have high conductivity. XRD cannot detect graphene, so no peaks corresponding to graphene are observed.

Experimental Example 2 Measurement of Raman Spectrum

The Raman spectrum of the cathode active material including NaTi ₂ (PO ₄ ) ₃ and graphene as the cathode active material prepared in Example 1 is shown in FIG. 3.

This is because strong peaks are observed in the 1350 cm ^-1 (D-disordered carbon) and 1581 cm ^-1 (G-graphitic carbon) region, it can be seen that the positive electrode active material is present.

The ratio of the D band to the G band (I _D / I _G ) is 1.05, which is typical of the reduced graphene oxide.

Experimental Example 3 TEM  Image measurement

The TEM image of the cathode active material including NaTi ₂ (PO ₄ ) ₃ and graphene prepared in Example 1 was measured and the results are shown in FIG. 4.

In FIG. 4, the darker shade is NaTi ₂ (PO ₄ ) ₃ particles, and the lighter shade is graphene. In Figure 4 it can be seen that the graphene is connected between each NaTi ₂ (PO ₄ ) ₃ particles. 4 is a graph showing HR-TEM (HR-TEM) of graphene. Lattice stripes are observed in the HR-TEM and the spacing between the faces of the lattice stripes is 0.37 nm. It can be seen that the graphene has a NASICON crystal structure, and has a very high ion conductivity. As such, NaTi ₂ (PO ₄ ) ₃ coated with graphene may improve performance of the hybrid capacitor.

<Example 2> As a cathode active material Graphene Nanosheet layer  Produce

The graphene oxide solution is prepared from natural graphite flakes by the modified Hummer Method and then dried to obtain graphene oxide. This was heat-treated at 700 ° C. for 2 hours under Ar / H ₂ (90% / 10%) atmosphere.

Experimental Example 4 XRD  Measure

As an anode active material prepared in Example 2, the XRD pattern of the graphene nanosheet layer was measured and the results are shown in FIG. 5.

In FIG. 5, a wide peak is observed around 24 °, and it can be seen that the graphene of the graphene nanosheet layer includes amorphous carbon having low graphitization.

Experimental Example 5 Measurement of Raman Spectrum

Raman spectrum of the graphene nanosheet layer as a negative electrode active material prepared in Example 2 was measured and the results are shown in FIG. 6.

This results in strong peaks in the 1370 cm ^-1 (D-disordered GNS) and 1600 cm ^-1 (G-graphitic carbon) regions.

Experimental Example 6 TEM  Image measurement

As a negative electrode active material prepared in Example 2, the TEM image of the graphene nanosheet layer was measured and the results are shown in FIG. 7. Referring to Figure 7 (a) it can be seen that there is an oxygen defect on the graphene surface has a folded structure. (b) is a result of measuring a high-resolution TEM image of the folded portion of the graphene nanosheets of one layer.

Referring to FIG. 7, it can be seen that graphene included in the graphene nanosheet layer generally includes a folded and wrinkled shape that appears when the graphene is heat treated. By the graphene nanosheet layer as described above it is possible to improve the electrical conductivity to achieve a good performance at high current.

Example 3 Sodium hybrid  Capacitor manufacturers

The positive electrode is a positive electrode active material including NaTi ₂ (PO ₄ ) ₃ and graphene prepared in Example 1, the additive Ketjen black and binder (Teflonized acetylene black) in a weight ratio of 80:10:10. After mixing, it was prepared by applying to a stainless steel mesh (area 200 mm) and drying in vacuo at 160 ° C. for 4 hours.

As the negative electrode, the graphene nanosheet layer prepared in Example 2 was used.

Coin cell CR2032 was assembled in a glove box filled with argon using the positive and negative electrodes.

At this time, the positive electrode and the negative electrode are separated by a porous polypropylene separator, 1 M NaClO ₄ as an electrolyte (in ethylene carbonate (EC) / dimethyl carbonate (DMC) (1: 1, v / v)) was used.

Experimental Example 7 Charging and discharging  curve

The charge and discharge curves of the sodium hybrid capacitors prepared in Example 3 are shown in FIG. 8.

In the Ti ^{4 +} / Ti ^{3 +} redox reaction, two reversible sodium ions per cell unit can exhibit very high energy density. Referring to Figure 8 it can be seen that the shape of the graph is not linear or triangular. This means the dual charge storage mechanism of the hybrid capacitor. The curve of the graph is a plateau (plateau) by the insertion / desorption of sodium ions by Ti redox reaction and the plateau (plateau) by the adsorption / desorption of anion to the graphene nanosheet layer. Further to its high current the curve maintains its own shape, which graphene nanosheet in accordance with the adsorption / desorption of the layer NaTi ₂ (PO _{4) 3} and Yes sodium ion intercalation / deintercalation in the interior the positive electrode active material comprising a pin It is meant to be easy. This shows that they have better thermodynamic performance than conventional hybrid capacitors.

Experimental Example 8 Measurement of Life Characteristics

A graph showing the lifespan characteristics of the sodium hybrid capacitor manufactured in Example 3 is shown in FIG. 9.

The lifetime characteristics are evaluated at high current densities of 4 A g ⁻¹ (Fig. 9 (b)), and the sodium hybrid capacitor according to the present invention is about 10 at initial coulombic efficiency despite more than 75,000 charge and discharge cycles. It can be seen that only about% decreases (Fig. 9 (a)).

Conventional hybrid capacitors have been reported to show a significant reduction even in 1,000 cycles, but the sodium hybrid capacitor according to the present invention produces only about 0.13% reduction per 1000 cycles. The same is true for a wide range of voltages from 0 to 3 V.

Experimental Example 9 Ragone  plot graph

10 and 11 show graphs of a Ragon plot of energy and power densities of the sodium hybrid capacitors prepared in Example 3. FIG.

The Ragone plot shows that the sodium hybrid capacitor according to the present invention has much higher energy than conventional hybrid capacitors with high energy loss at high power using AC and CNTs at the electrode where adsorption takes place.

Sodium hybrid capacitor according to the embodiment of the invention is about 34 Whkg after 75,000 charge-discharge ^cycles can transmit the ^first energy. This means that there is about 0.13% loss over the initial energy density per 1,000 cycles. Since this performance of conserving energy at high power has good durability, the naturium hybrid capacitor according to the embodiment of the present invention is stable and durable, and can be easily applied to a large electric vehicle.

Experimental Example 10 Nyquist  plot graph

A Nyquist plot graph comparing before and after a charge / discharge cycle of the sodium hybrid capacitor prepared in Example 3 is shown in FIG. 12.

The semicircular curves at high frequencies show the transfer of charges at the electrode and electrolyte interfaces, while the slope curves at low frequencies show the insertion and desorption of sodium.

The graph also shows that there is only a slight change by solution resistance after the cycle. Through this, it can be seen that the positive electrode active material included in the sodium hybrid capacitor according to the embodiment of the present invention is easily inserted because sodium is activated after the charge / discharge cycle.

Experimental Example 11 XRD  Measure

The XRD pattern of the positive electrode active material including NaTi ₂ (PO ₄ ) ₃ and graphene after the charge and discharge cycle of the sodium hybrid capacitor prepared in Example 3 is shown in FIG. 13.

Referring to FIG. 13, it can be seen that the pattern of the stable NASICON structure is maintained even after the cycle.

The sodium hybrid capacitor according to the embodiment of the present invention may enable high energy density by allowing sodium ions to be easily inserted into the electrode. In addition, the graphene of the positive electrode active material may improve the mobility of sodium ions to increase the electrical conductivity. In addition, it maintains stability even after the charge and discharge cycle, and maintains high electrical conductivity and high energy density.

In addition, it can be seen that the sodium hybrid capacitor according to the embodiment of the present invention has superior performance as compared to the case of using only sodium compound or graphene as a negative electrode active material.

Claims (10)

A positive electrode including a positive electrode active material;
A negative electrode including a negative electrode active material; And
An electrolyte which mediates the insertion and desorption of ions between the positive electrode active material and the negative electrode active material,
The positive electrode active material includes a sodium compound and graphene,
The negative electrode active material includes graphene,
Graphene included in the negative electrode active material is a graphene nanosheet layer,
The negative electrode includes a negative electrode current collector disposed on one surface of the negative electrode active material,
The negative electrode active material is oriented perpendicular to one surface of the negative electrode current collector,
Sodium hybrid capacitors.
The method of claim 1,
The sodium compound includes a substance represented by the following formula (1)
Sodium hybrid capacitor:
[Formula 1] Na _x M _y (PO ₄ ) _z
(Transition metal M is one or two or more metal elements selected from V, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Sn, Sb, Bi, Ta and W, 0 <x ≦ 4, 0 <y ≦ 3, 1 ≦ z ≦ 3).
The method of claim 1,
The sodium compound is characterized in that it comprises NaTi ₂ (PO ₄ ) ₃
Sodium hybrid capacitors.
delete delete Preparing a cathode coated with a cathode active material on one surface of a current collector;
Preparing a negative electrode having a negative electrode active material coated on one surface of a current collector; And
Disposing the positive electrode and the negative electrode such that an electrolyte which mediates the insertion and desorption of ions is disposed between the positive electrode and the negative electrode;
The positive electrode active material includes a sodium compound and graphene,
The negative electrode active material includes graphene,
Graphene included in the negative electrode active material is a graphene nanosheet layer,
The negative electrode includes a negative electrode current collector disposed on one surface of the negative electrode active material,
The negative electrode active material is oriented perpendicular to one surface of the negative electrode current collector,
Method of making sodium hybrid capacitors.
The method of claim 6,
The sodium compound includes a substance represented by the following formula (1)
Method of manufacturing sodium hybrid capacitors:
[Formula 1] Na _x M _y (PO ₄ ) _z
(Transition metal M is one or two or more metal elements selected from V, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Sn, Sb, Bi, Ta and W, 0 <x ≦ 4, 0 <y ≦ 3, 1 ≦ z ≦ 3).
The method of claim 6,
The sodium compound is characterized in that it comprises NaTi ₂ (PO ₄ ) ₃
Method of making sodium hybrid capacitors.



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