KR102627218B1 - Electrode Active Material and Capacitor including this - Google Patents

Abstract

The present invention can provide an electrode active material having a hierarchical porous carbon network with excellent specific surface area and total pore volume characteristics. The present invention can provide a capacitor that includes the electrode active material described above and has excellent electrical conductivity, high energy density and power density, and excellent stability.

Description

Electrode active material and capacitor including this}

The present invention relates to electrode active materials and capacitors containing the same.

This invention was carried out under the Ministry of Science and ICT's Global Frontier Project ( C1-6401 ).

Electrochemical capacitors (supercapacitors) have fast charge/discharge characteristics, excellent stability, and excellent energy density and power density, and have dominated electrochemical energy storage systems for the past 20 years.

As a first-generation supercapacitor, research has been conducted on electric double layer capacitors. Electric double layer capacitors generally use carbon materials with a high specific surface area (e.g., carbon nanotubes, graphene, activated carbon, or natural carbon, etc.) as electrode materials to store charges in the electrode and electrolyte through a non-faradaic process. It is a principle. These electric double-layer capacitors have fast charge/discharge characteristics, excellent cycle life, and surplus potential characteristics that enable high-speed power supply, but their low energy supply required performance improvement in commercial terms.

In order to improve these problems of the first generation super capacitor, research was conducted on asymmetric/hybrid super capacitors as second generation capacitors. Asymmetric/hybrid capacitors consist of a pair of carbon electrodes and a high-capacitance Faradaic electrode to harvest charge using Faradaic and non-Faradaic phenomena. These asymmetric/hybrid capacitors have the advantage of having a commercially viable cycle life and high energy density.

However, due to the increase in energy demand and utilization for various purposes, the need for capacitors with characteristics superior to those of asymmetric/hybrid capacitors, such as energy density and power density, has increased. Accordingly, super redox capacitors (3rd generation capacitors) are emerging, in which the carbon electrodes of asymmetric/hybrid supercapacitors are replaced with other omni-type materials with useful electrochemical advantages.

Super redox capacitors are capacitors that have the advantage of providing high energy density and power density while providing excellent stability due to higher battery voltage compared to asymmetric/hybrid capacitors. To realize these features of a super redox capacitor, it is necessary to select useful electrodes capable of operating at high potentials.

One purpose of the present invention is to provide an electrode active material having a hierarchical porous carbon network with excellent specific surface area and total pore volume characteristics. Another object of the present invention is to provide a capacitor that includes the above electrode active material and has excellent electrical conductivity, high energy density and power density, and excellent stability.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

One aspect of the present invention relates to electrode active materials.

The electrode active material of the present invention includes, for example, hierarchical carbon particles; A composite of the hierarchical carbon particle body and LVO (LVO/C composite); Or it may be a composite of the hierarchical carbon particles and LVP (LVP/C composite).

For example, the composite of the hierarchical carbon particles and LVO (LVO/C composite) may include the hierarchical carbon particles in the range of 500 to 9500 parts by weight based on 100 parts by weight of the LVO.

For example, the composite of the hierarchical carbon particles and LVP (LVP/C composite) may include the hierarchical carbon particles in the range of 500 to 9500 parts by weight based on 100 parts by weight of the LVP.

The electrode active material of the present invention, for example, hierarchical carbon particles, may include an inlet with a size in the range of 1 nm to 500 nm that can enter internal pores on the surface, and macro pores and meso pores on the inside. It may include at least two types of pores and micro pores, and the hierarchical carbon particle is a hierarchical porous carbon network in which at least two types of pores among the macro pores, meso pores, and micro pores are interconnected. It can be characterized by forming a .

For example, the hierarchical carbon particles may be obtained by ion-exchanging a hydroxyl group-containing resin with potassium cations (K+) and carbonizing it. The hydroxyl group-containing resin may be, for example, Phenol Formaldehyde Resin.

For example, the electrode active material of the present invention may exhibit a D-band peak within a wavelength range of 1300 to 1400 cm-1 and a G-band peak within a wavelength range of 1550 to 1620 cm-1 according to Raman spectroscopy. and may include hierarchical carbon particles, wherein the intensity ratio (D/G) of the D band to the G band is 0.7 to 1.5.

For example, the electrode active material of the present invention may include hierarchical carbon particles having a BET specific surface area of 830 m2/g or more.

For example, the electrode active material of the present invention may include hierarchical carbon particles having a total pore volume of 0.4 cm3/g or more.

The electrode active material of the present invention may include, for example, hierarchical carbon particles where the average size of the micro pores may range from 0.7 to 2.0 nm, and the micro pore volume may range from 0.35 to 1.5 cm3/g. .

The hierarchical carbon particle body may have a spherical bead shape, for example.

Another aspect of the present invention relates to capacitors.

Capacitors of the present invention may include, for example, hierarchical carbon particles; A composite of the hierarchical carbon particle body and LVO (LVO/C composite); Alternatively, it may include at least one of the hierarchical carbon particles and a composite of LVP (LVP/C composite).

Capacitors of the present invention include, for example, composites of hierarchical carbon particles and LVO (LVO/C composite); Alternatively, it may include at least one of the hierarchical carbon particles and a composite of LVP (LVP/C composite).

For example, the capacitor of the present invention may have a power density of 10 kW/kh or more and an energy density of 90 Wh/kg or more.

The present invention can provide an electrode active material having a hierarchical porous carbon network with excellent specific surface area and total pore volume characteristics. The present invention can provide a capacitor that includes the electrode active material described above and has excellent electrical conductivity, high energy density and power density, and excellent stability.

Figure 1 shows a schematic diagram of the LVO/C complex or LVP/C complex of the present invention.
Figure 2 is an image taken of LVO powder (Preparation Example 4).
Figure 3 shows an SEM image of LVO powder (Preparation Example 4).
Figure 4 is an XRD graph for LVO (Preparation Example 4) (top: experimental value, bottom: literature value).
Figure 5 is an image taken of LVP powder (Preparation Example 5).
Figure 6 shows an SEM image of LVP powder (Preparation Example 5).
Figure 7 is an XRD graph for LVP (Preparation Example 5) (top: experimental value, bottom: literature value)
Figure 8 shows LVO/C composite (top, LVO/K2CO3-CPFR nanocomposite of Preparation Example 6), LVO powder (middle, Preparation Example 4), and hierarchical carbon particles (bottom, K2CO3-CPFR nanocomposite of Preparation Example 2). This is a comparison of the XRD graph for CPFR).
Figure 9 shows an SEM image of the LVO/C composite (LVO/K2CO3-CPFR nanocomposite of Preparation Example 6).
Figure 10 shows LVP/C composite (top, LVP/K2CO3-CPFR nanocomposite of Preparation Example 8), LVP powder (middle, Preparation Example 5), and hierarchical carbon particles (bottom, K2CO3-CPFR nanocomposite of Preparation Example 2). This is a comparison of the XRD graph for CPFR).
Figure 11 shows an SEM image of the LVP/C composite (LVP/K2CO3-CPFR nanocomposite of Preparation Example 8).
Figure 12 shows CV curves measured at different scan speeds for the coin cell of Example 1.
Figure 13 is a graph comparing CV curves for the coin cells of Example 1 and Comparative Example 1.
Figure 14 is a graph showing galvanostat charge/discharge curves measured at different current densities for the coin cell of Example 1.
Figure 15 is a graph measuring the specific capacity according to the number of cycles while varying the current density for the coin cell of Example 1.
Figure 16 shows an SEM image of PFR beads (Preparation Example 1).
Figure 17 shows an SEM image of K2CO3-CPFR beads (Preparation Example 2).
Figure 18 shows an SEM image of KOH-CPFR beads (Preparation Example 3).
Figure 19 shows UV-Vis DRS graphs for PFR (black, Preparation Example 1), K2CO3-CPFR (blue, Preparation Example 2), and KOH-CPFR (red, Preparation Example 3).
Figure 20 shows FT-IR spectra for PFR (black, Preparation Example 1), K2CO3-CPFR (blue, Preparation Example 2), and KOH-CPFR (red, Preparation Example 3).
Figure 21 shows the results of SEM-EDX mapping analysis for K2CO3-CPFR (Preparation Example 2) (a) and KOH-CPFR (Preparation Example 3) (b).
Figure 22 is a graph measuring pore size distribution by NLDFT method for PFR (black, Preparation Example 1), K2CO3-CPFR (blue, Preparation Example 2), and KOH-CPFR (red, Preparation Example 3) (insert) The image is a graph showing the distribution of micropores with a diameter of less than 2 nm).
Figure 23 shows a TEM image of K2CO3-CPFR (Preparation Example 2).
Figure 24 is a graph showing the results of Raman spectroscopy for K2CO3-CPFR (blue, Preparation Example 2) and KOH-CPFR (red, Preparation Example 3).
Figure 25 is a graph showing N2 adsorption isotherms for PFR (black, Preparation Example 1), K2CO3-CPFR (blue, Preparation Example 2), and KOH-CPFR (red, Preparation Example 3).

Among the physical properties mentioned in this specification, the physical properties where measurement temperature and/or measurement pressure affect the results are the results of measurements at room temperature and/or pressure, unless specifically stated otherwise.

The term room temperature refers to a natural temperature that is not heated or reduced, for example, any temperature in the range of 10°C to 30°C, about 23°C, or about 25°C. Additionally, in this specification, the unit of temperature is °C unless otherwise specified.

The term normal pressure is the natural pressure that is not pressurized or decompressed, and usually means about 1 atmosphere of atmospheric pressure.

In the case of a physical property in which the measured humidity affects the results in this specification, unless otherwise specified, the physical property is a physical property measured at room temperature and/or normal pressure with natural humidity that is not specifically adjusted.

One aspect of the present invention relates to electrode active materials.

The electrode active material of the present invention includes, for example, hierarchical carbon particles; A composite of the hierarchical carbon particles and LVO (hereinafter referred to as LVO/C composite); Alternatively, it may be a composite of the hierarchical carbon particles and LVP (hereinafter referred to as LVP/C composite). In this specification, the term LVO means Li ₃ VO ₄ and the term LVP means Li ₃ V ₂ (PO ₄ ) ₃ .

For example, the hierarchical carbon particles may include micro pores, meso pores, and/or macro pores having different pore sizes. Pore size herein may mean, for example, maximum pore diameter, minimum pore diameter, and/or average pore diameter. As used herein, the terms micro pore, meso pore, and macro pore can each mean a pore size of less than 2 nm, in the range of 2 nm to 50 nm, and greater than 50 nm. The hierarchical carbon particle body may include micro-pores and meso-pores (blue), for example, as shown in Figure 22, or may include micro-pores, meso-pores, and macro-pores (red), and has a specific surface area and/or Alternatively, from the viewpoint of total pore volume, etc., it may more preferably include micro-pores and meso-pores (blue).

The hierarchical carbon particles of the present invention may have pores with different pore sizes hierarchically interconnected with each other. In one example, the hierarchical carbon particle body of the present invention may include an inlet with a size in the range of 1 nm to 500 nm capable of entering internal pores on the surface of the carbon particle body, and macro pores and micro pores therein. ) It may include at least two types of pores and meso pores. The size of the inlet may mean the minimum diameter, maximum diameter, and/or average diameter of the inlet. In another example, the size of the inlet formed on the surface of the carbon particle may be in the range of 5 nm to 300 nm or in the range of 10 nm to 100 nm. The hierarchical carbon particles of the present invention are characterized in that at least two types of pores among the macro pores, micro pores, and meso pores are interconnected to form a hierarchical porous carbon network. (see Figure 23).

The hierarchical carbon particles of the present invention can be characterized as being obtained, for example, by ion-exchanging a hydroxy group-containing resin with potassium cations (K ⁺ ). Through this, the formation of hierarchical carbon particles having the above-described characteristics may be possible.

The hydroxy group-containing resin may be, for example, phenol formaldehyde resin (PFR). The phenol formaldehyde resin has a high carbon content, has a spherical shape, and has a uniform shape, so it may be suitable for introduction as a raw material for the hierarchical carbon particles of the present invention.

By ion-exchanging potassium cations (K+) with the hydroxyl group-containing resin, deprotonation of the hydroxyl group may proceed, thereby making it possible to implement a unique hierarchical porous carbon particle. That is, the hierarchical carbon particles of the present invention can have a unique open surface and at the same time exhibit hierarchical pore size distribution by ion-exchanging the hydroxyl group-containing resin as described above with potassium cations (K+).

For example, the hierarchical carbon particles of the present invention may contain 10 parts by weight or less of potassium based on 100 parts by weight of the hydroxy group-containing resin. In another example, the hierarchical carbon particles of the present invention contain potassium in an amount of 9.5 parts by weight or less, 9 parts by weight or less, 8.5 parts by weight or less, 8 parts by weight or less, 7.5 parts by weight or less, and 7 parts by weight or less, based on 100 parts by weight of the hydroxyl group-containing resin. Hereinafter, it may be included in 6.5 parts by weight or less or 6 parts by weight or less. The hierarchical carbon particles of the present invention contain potassium in this weight range, so that at least two types of macropores, mesopores, and/or micropores can be interconnected to form a hierarchical carbon network. In terms of realizing characteristics such as high specific surface area and/or total pore volume, the hierarchical carbon particles of the present invention more preferably contain potassium in an amount of 5.5 parts by weight or less, 5 parts by weight or less, based on 100 parts by weight of the hydroxyl group-containing resin. It may contain 4.5 parts by weight or less, 4 parts by weight or less, 3.5 parts by weight or less, 3 parts by weight or less, 2.5 parts by weight or less, or 2 parts by weight or less. The lower limit of the potassium content is not particularly limited, but for example, 0.1 part by weight or more, 0.2 part by weight or more, 0.3 part by weight or more, 0.4 part by weight or more, 0.5 part by weight or more, 0.6 part by weight based on 100 parts by weight of the hydroxyl group-containing resin. or more, 0.7 parts by weight or more, 0.8 parts by weight or more, 0.9 parts by weight or more, 1 or more parts by weight, 1.1 parts by weight or more, 1.2 parts by weight or more, 1.3 parts by weight or more, 1.4 parts by weight or more, 1.5 parts by weight or more, or 1.6 parts by weight. It may include more.

The hierarchical carbon particle body of the present invention may have, for example, a uniform distribution of potassium ions. Potassium ion distribution can be confirmed according to the evaluation example described later. In one example, the hierarchical carbon particles of the present invention may have a potassium ion distribution as shown in FIGS. 21A and 21B, and more preferably, may have a potassium ion distribution as shown in FIG. 21A.

The hierarchical carbon particle body of the present invention can also be characterized as being obtained, for example, by ion-exchanging a hydroxy group-containing resin with potassium cations (K ⁺ ) and carbonizing it. For example, the carbonization may be performed at a temperature of 700 to 1100° C. under an inert gas. For example, the inert gas may be nitrogen (N ₂ ), argon (Ar), or helium (He). In other examples, the temperature may be 750 ℃ or more, 800 ℃ or more, or 850 ℃ or less, or 1050 ℃ or less, 1000 ℃ or less, or 950 ℃ or less, but is not limited thereto, and is determined by the shape and use of the desired hierarchical carbon particle. It can be appropriately controlled by considering the following. The hierarchical carbon particles of the present invention can form the desired unique hierarchical porous carbon network by going through the carbonization step described above.

The hierarchical carbon particles of the present invention may, for example, be in the form of spherical beads. The shape of the hierarchical carbon particles may be influenced by the type of raw material and/or carbonization conditions. In one example, the hierarchical carbon particles of the present invention are formed from a phenol formaldehyde resin having a spherical and uniform shape, and can have a spherical bead shape as described above by going through the carbonization conditions described above. Accordingly, the hierarchical carbon particles of the present invention can achieve physical stability and high packing density.

The hierarchical carbon particles of the present invention may have a BET specific surface area of, for example, at least 830 m ² /g. The BET specific surface area can be measured according to the evaluation example described later. The hierarchical carbon particles of the present invention are more preferably 840 m ² /g or more, 850 m ² /g or more, 860 m 2 /g or more, 870 m ² /g or more, 880 m ² /g or more, 890 m ² /g or more. m ² /g or more, 900 m ² /g or more, 910 m ² /g or more, 920 m ² /g or more, 930 m ² /g or more, 940 m ² /g or more, 950 m ² /g or more, 960 m ² /g or more, 970 m ² /g or more, 980 m ² /g or more, 990 m ² /g or more, 1000 m ² /g or more, 1050 m ² /g or more, 1100 m ² /g or more, 1150 m ² /g or more, 1200 m ² /g or more, 1250 m ² /g or more, or 1300 m ² /g or more. The upper limit of the BET specific surface area of the hierarchical carbon particles of the present invention is not particularly limited, but is 10000 m ² /g or less, 8000 m ² /g or less, 6000 m ² /g or less, 4000 m 2 /g or less, or 2000 m ² /g or less. It may be about m ² /g or less.

The hierarchical carbon particles of the present invention may have a total pore volume of, for example, at least 0.4 cm3/g. The total pore volume can be measured according to the evaluation example described later. For example, the total pore volume may mean the total pore volume under the condition of P/P0=0.990. In other examples, the hierarchical carbon particles of the present invention may have a total pore volume of at least 0.42 cm3/g, at least 0.44 cm3/g, at least 0.46 cm3/g, or at least 0.48 cm3/g, and more preferably at least 0.5 cm3/g. g or more, 0.6 cm3/g or more, 0.7 cm3/g or more, 0.8 cm3/g or more, or 0.9 cm3/g or more. The upper limit of the total pore volume is not particularly limited, but may be about 2 cm3/g or less or 1.5 cm3/g or less.

The hierarchical carbon particles of the present invention may, for example, have micro pore sizes in the range of 0.7 to 2.0 nm and micro pore volumes in the range of 0.35 to 1.5 cm3/g. In another example, the hierarchical carbon particle of the present invention may have a micropore size of 0.75 nm or more, 0.8 nm or more, or 0.9 nm or more, 1.8 nm or less, 1.6 nm or less, or 1.4 nm or less, and more preferably 1.2 nm or less. It may be less than or equal to 1.0 nm.

The hierarchical carbon particles of the present invention may have excellent BET specific surface area characteristics, total pore volume characteristics, and/or micro pore characteristics through the unique hierarchical porous carbon network described above. Accordingly, when introduced into an energy storage device (e.g., a capacitor, etc.) described later, the mobility of lithium ions and electrolyte impregnation can be improved, and thus excellent capacity and electrical conductivity can be achieved. .

The hierarchical carbon particles of the present invention can also exhibit a D-band peak within the wavelength range of 1300 to 1400 cm ^-1 and a G-band peak within the wavelength range of 1550 to 1620 cm ^-1 according to Raman spectroscopy, for example. It may represent a peak, and the intensity ratio (D/G) of the D band to the G band may be 0.7 to 1.5. The D band represents disordered graphitic carbon, and the G band represents ordered graphitic carbon. The D/G intensity ratio may increase in value, for example, when defective sites in the hierarchical carbon particles are distinct. In one example, the potassium cation exchanged hierarchical carbon particle body may have increased defect sites due to the reaction of potassium cations and carbon, thereby increasing the D/G intensity ratio. In other examples, the D/G intensity ratio is 0.75 or more, 0.8 or more, 0.85 or more, 0.9 or more, 0.91 or more, 0.92 or more, 0.93 or more, 0.94 or more, 0.95 or more, 0.96 or more, 0.97 or more, 0.98 or more, or 0.99 or more. , may be 1.4 or less, 1.3 or less, 1.2 or less, or 1.1 or less, and more preferably 1.0 or less. By having the above D/G strength ratio, the hierarchical carbon particles of the present invention can exhibit excellent durability while having appropriate defect sites.

In the present specification, the LVO/C composite may refer, for example, to a compound in which hierarchical carbon particles having the above-mentioned characteristics and LVO are physically or chemically bonded to each other by interacting with each other, preferably as shown in Figure 1 As shown, it may be a compound in which the hierarchical carbon particles and LVO are physically bonded to each other by interacting with each other.

For example, the LVO/C composite may include the hierarchical carbon particles in the range of 500 to 9500 parts by weight based on 100 parts by weight of the LVO. In another example, the LVO/C composite includes 550 parts by weight or more, 600 parts by weight, 650 parts by weight, 700 parts by weight, 750 parts by weight, or 800 parts by weight based on 100 parts by weight of the LVO. 850 parts by weight or more, 9000 parts by weight or less, 8500 parts by weight or less, 8000 parts by weight or less, 7500 parts by weight or less, 7000 parts by weight or less, 6500 parts by weight or less, 6000 parts by weight or less, 5500 parts by weight or less, It may include 5000 parts by weight or less, 4500 parts by weight, 4000 parts by weight or less, 3500 parts by weight or less, 3000 parts by weight or less, 2500 parts by weight, 2000 parts by weight or less, 1500 parts by weight or less, or 1000 parts by weight or less.

For example, the LVO/C composite may include the LVO on the surface or inside of the hierarchical carbon particles, and preferably may include the LVO on the surface and inside the hierarchical carbon particles. LVO may be uniformly distributed on the surface and/or interior of the hierarchical carbon particle body. As described above, LVO, which has high theoretical capacity, high speed, and excellent reversibility, is added to hierarchical carbon particles having excellent specific surface area and/or total pore volume characteristics through a unique hierarchical porous structure at an appropriate weight ratio and By combining them in this way, the effects of capacity characteristics and electrical conduction characteristics may be more significantly expressed, and thus it may be possible to provide an energy storage device with significantly excellent energy density and power density.

In the present specification, the LVP/C complex may mean, for example, a compound in which hierarchical carbon particles having the above characteristics and LVP are physically or chemically bonded to each other by interacting with each other, preferably as shown in Figures 1 and 1. Likewise, it may be a compound in which the hierarchical carbon particles and LVP physically interact with each other and are bonded.

For example, the LVP/C composite may include the hierarchical carbon particles in the range of 500 to 9500 parts by weight based on 100 parts by weight of the LVP. In another example, the LVO/C composite includes 550 parts by weight or more, 600 parts by weight, 650 parts by weight, 700 parts by weight, 750 parts by weight, or 800 parts by weight based on 100 parts by weight of the LVO. 850 parts by weight or more, 9000 parts by weight or less, 8500 parts by weight or less, 8000 parts by weight or less, 7500 parts by weight or less, 7000 parts by weight or less, 6500 parts by weight or less, 6000 parts by weight or less, 5500 parts by weight or less, It may include 5000 parts by weight or less, 4500 parts by weight, 4000 parts by weight or less, 3500 parts by weight or less, 3000 parts by weight or less, 2500 parts by weight, 2000 parts by weight or less, 1500 parts by weight or less, or 1000 parts by weight or less.

For example, the LVP/C composite may include the LVP on the surface or inside of the hierarchical carbon particles, and preferably may include the LVP on the surface and inside the hierarchical carbon particles. LVP may be uniformly distributed on the surface and/or interior of the hierarchical carbon particle body. As described above, by complexing LVP with carbon having excellent specific surface area and/or total pore volume characteristics through a unique hierarchical porous structure, high reversible capacity and fast lithium ion mobility, at an appropriate weight ratio and method, The effects of capacity characteristics and electrical conduction characteristics may be more significantly expressed, and thus it may be possible to provide an energy storage device with significantly superior energy density and power density.

In the present invention, the hierarchical carbon particles, LVO/C composite, and LVP/C composite can each be manufactured according to the following steps. The above-described content may be equally applied to the following content.

The hierarchical carbon particles of the present invention include, for example, preparing a hydroxy group-containing resin; Ion-exchanging the hydroxyl group-containing resin by immersing it in an aqueous solution containing potassium cations (K+); and/or carbonizing the ion-exchanged resin to obtain hierarchical carbon particles; It can be obtained through .

The potassium cation-containing aqueous solution may be, for example, a K ₂ CO ₃ aqueous solution or a KOH aqueous solution, and is preferably a K ₂ CO ₃ aqueous solution in terms of realizing a better specific surface area and total pore volume. The molar concentration of the potassium cation-containing aqueous solution may be, for example, in the range of 0.05 M to 1.5 M.

The step of ion-exchanging the hydroxyl group-containing resin by immersing it in the potassium cation-containing aqueous solution may be performed, for example, at a temperature in the range of 30 to 100° C. for 4 to 12 hours. In other examples, the temperature may be 40°C or higher, 50°C or higher, or 90°C or lower, 80°C or lower, or 70°C or lower. In other examples, the time may be 5 hours or more, 6 hours or more, or 7 hours or more, or 11 hours or less, 10 hours or less, or 9 hours or less.

For example, the step of carbonizing the ion-exchanged resin to obtain hierarchical carbon particles may be the same as the carbonization described above.

The hierarchical carbon particles of the present invention may also be obtained, for example, by additionally undergoing hydrothermal treatment and acidification steps. The hydrothermal treatment and acidification steps may include, for example, washing with hydrochloric acid and drying at a temperature range of 60°C to 140°C. In other examples, the temperature may be 70°C or higher, 80°C or higher, or 90°C or higher, or 130°C or lower, 120°C or lower, or 110°C or lower.

Another aspect of the present invention relates to capacitors.

Capacitors of the present invention may include, for example, hierarchical carbon particles; A composite of the hierarchical carbon particle body and LVO (LVO/C composite); Alternatively, it may include at least one of the hierarchical carbon particles and a composite of LVP (LVP/C composite). The above-mentioned information may be applied in the same manner as to matters regarding the hierarchical carbon particles, etc.

The capacitor of the present invention may include, for example, a cathode active material and an anode active material, wherein the cathode active material includes hierarchical carbon particles; and LVP/C composite, wherein the anode active material includes the hierarchical carbon particles; and LVO/C complex. In terms of realizing characteristics such as excellent capacity, electrical conductivity, energy density, and power density, the capacitor of the present invention may preferably include at least one type of LVP/C composite or LVO/C composite.

For example, the capacitor of the present invention may have an energy density of 90 Wh/kg or more and a power density of 10 kW/kg or more. In other examples, the energy density may be 95 Wh/kg or more, 100 Wh/kg or more, 105 Wh/kg or more, 110 Wh/kg or more, 115 Wh/kg or more, 120 Wh/kg or more, or 125 Wh/kg or more. there is. In other examples, the power density is 10.5 kW/kg or more, 11 kW/kg or more, 11.5 kW/kg or more, 12 kW/kg or more, 12.5 kW/kg or more, 13 kW/kg or more, 13.5 kW/kg or more. It can be more than 14 kW/kg.

The capacitor of the present invention includes, for example, a cathode electrode slurry layer containing the cathode active material; It may include an anode electrode slurry layer containing the anode active material.

Each of the cathode electrode slurry layer and the anode electrode slurry layer may further include, for example, a conductive material. The conductive material includes graphite such as natural graphite or artificial graphite; Carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, summer black, and carbon fiber; Metal powders or metal fibers such as copper, nickel, aluminum, and silver; Conductive whiskeys such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Alternatively, conductive polymers such as polyphenylene derivatives may be used, but are not limited thereto, and known conductive materials may be appropriately selected within the range that do not impair the characteristics of the capacitor.

Each of the cathode electrode slurry layer and the anode electrode slurry layer may further include, for example, a binder. The binder may be one or more selected from the group consisting of CMC (Carboxymethylcellulose), PVA (Polyvinyl alcohol), PVDF (Polyvinyliene fluoride), PVP (Polyvinylpyrrolidone), and MC (Methyl cellulose), but is not limited thereto, and is not limited to the capacitor. Known binders can be appropriately selected within the range that do not impair the properties.

For example, the cathode active material may be included in an amount of 60 parts by weight or more based on 100 parts by weight of the cathode electrode slurry layer. In another example, the cathode active material may be included in an amount of 65 parts by weight or more, 70 parts by weight, 75 parts by weight or more, or 80 parts by weight or less, or 95 parts by weight or less, or 90 parts by weight or less, based on 100 parts by weight of the cathode electrode slurry layer. You can.

For example, the anode active material may be included in an amount of 60 parts by weight or more based on 100 parts by weight of the anode electrode slurry layer. In another example, the anode active material may be included in an amount of 65 parts by weight or more, 70 parts by weight, 75 parts by weight or more, or 80 parts by weight or less, or 95 parts by weight or less, or 90 parts by weight or less, based on 100 parts by weight of the anode electrode slurry layer. You can.

The capacitor of the present invention may also further include, for example, a current collector. The current collector may be, for example, a cathode current collector or an anode current collector, and the cathode current collector or anode current collector may be prepared according to a known conventional method or a modified method thereof without particular limitation. The current collector is not particularly limited as long as it is conductive without causing chemical changes in the capacitor. For example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, or carbon or nickel on the surface of aluminum or stainless steel. , titanium, silver, etc. can be used. The current collector can strengthen the binding force of the active material by forming fine irregularities on its surface, and can be used in various forms such as films, foils, sheets, nets, porous materials, foams, or non-woven fabrics.

The thickness of the current collector may be, for example, about 1㎛ to 100㎛. In other examples, the thickness of the current collector is 5 μm or more, 10 μm or more, 15 μm or more, or 20 μm or more, or 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, or 40 μm or less. Or it may be 30㎛ or less.

The capacitor of the present invention may also further comprise, for example, an electrolyte. The electrolyte may be, for example, an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, or a molten inorganic electrolyte, but is not limited thereto.

The capacitor of the present invention may also further include, for example, a separator (however, if the electrolyte is a polymer electrolyte, etc., it may not be included). The separator may include, but is not limited to, uniaxial and/or biaxial polypropylene, polyethylene, and/or polyolefin, and a known separator may be appropriately selected and used.

The capacitor of the present invention may additionally include other components that may be generally included.

Hereinafter, embodiments of the present application will be described in detail, but the present invention is not limited thereto and should be understood as including the present invention.

Preparation Example 1. Synthesis of PFR (Phenol Formaldehyde Resin) beads

Phenol (Kolon Aldrich, 99%) (4.7055g, 0.05mol) and hexamethylene tetramine (HMR, 99%) (3.50465g, 0.025mol) were dispersed in 20 ml of water and stirred at 80°C for 30 minutes. The solution was then placed in a Teflon-lined autoclave, 0.25 ml of ammonia (JUNSEI, 28%) solution was added, and the solution was heated at 200°C for 12 hours. Afterwards, it was cooled to room temperature to obtain a yellow powder product. The yellow powder product was washed repeatedly with water and then dried at 110°C for 2 hours. As a result, 3.20 g of PFR beads (yellow powder particles) were obtained.

Preparation Example 2. Synthesis of K2CO3 treated CPFR (Carbonized Phenol Formaldehyde Resin) beads

0.1M K2CO3 (Aldrich Corp., 99%) was added to the PFR beads of Preparation Example 1 and stirred at 60°C for 8 hours. This process was repeated 3 to 4 times until the pH of the solution did not change, thereby obtaining K2CO3-treated PFR beads (hereinafter referred to as K2CO3-PFR beads).

Next, the K2CO3-PFR beads were transferred to a ceramic boat, placed in a tubular furnace, and sintered (carbonized) at a temperature of 900° C. under a nitrogen atmosphere for 2 hours. After sintering, the carbonized material was washed three times with 1.0 M hydrochloric acid (Samchun, 37%), washed twice more with water, and dried at a temperature of 100°C (hydrothermal treatment/acidification). As a result, K2CO3-treated CPFR (hereinafter referred to as K2CO3-CPFR beads) was obtained (brown powder particles).

Preparation Example 3. Synthesis of KOH-treated CPFR (Carbonized Phenol Formaldehyde Resin) beads

KOH-treated PFR beads (hereinafter referred to as KOH-PFR beads) were obtained in the same manner as Preparation Example 2, except that 0.1M KOH (Aldrich Corp., 99%) was added to the PFR beads of Preparation Example 1. .

Subsequently, KOH-treated CPFR (hereinafter referred to as KOH-CPFR beads) was obtained in the same manner as Preparation Example 2, except that the KOH-PFR beads were carbonized (dark brown powder particles).

Evaluation Example 1. Scanning Electron Microscope (SEM)

SEM images of Preparation Examples 1 to 3 were obtained in a known manner using a HITACHI S-4800 device.

It was confirmed that the PFR of Preparation Example 1 had a spherical (about 7㎛ diameter) smooth bead shape as shown in FIG. 16.

The shapes of K2CO3-CPFR of Preparation Example 2 (see FIG. 17) and KOH-CPFR of Preparation Example 3 were confirmed through SEM. As a result, it was confirmed that K2CO3-CPFR and KOH-CPFR each had a uniform spherical bead shape with a particle diameter in the range of 5㎛ to 7㎛. In addition, K2CO3-CPFR and KOH-CPFR each underwent hydrothermal treatment and acidification steps, and it was confirmed that numerous inlets with a diameter of several tens of nanometers were formed on the surface through the intrusion of H ⁺ ions (see Figures 17 and 18). .

Evaluation Example 2. Ultraviolet-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS; UV-Vis Diffuse Reflectance Spectroscopy)

The UV-Vis DRS spectra of Preparation Examples 1 to 3 were measured using a UV-Vis spectrophotometer (UV-2600, Shimadzu) in a known manner. As a result, it was confirmed that it had different light absorption characteristics depending on whether or not it was treated with potassium cations, as shown in Figure 19.

Specifically, the K2CO3-CPFR (blue) of Preparation Example 2 treated with potassium cations (blue) and the KOH-CPFR (red) of Preparation Example 3 have a wavelength range of 200 nm to 800 nm compared to the PFR (black) of Preparation Example 1 without potassium cation treatment. The adsorption strength was higher, and the adsorption strength for visible light was particularly high.

This is inferred to be a result of the deprotonation of the OH group of the phenol resin. In particular, deprotonation of the OH group of the phenol resin by the strong base KOH seems to lead to higher visible light absorption (KOH treatment is a strong base promotes more potassium cation exchange with PFR beads).

Evaluation Example 3. FT-IR spectrum

The FT-IR spectra of Preparation Examples 1 to 3 were measured using a Thermo NICOLET 6700 spectrometer in a known manner. As a result, as shown in Figure 20, in the case of potassium ion exchanged KOH-CPFR (red) and K2CO3-CPFR (blue), the O-H peak of the phenolic resin at 3336 cm-1 was significantly reduced, while other vibration peaks were intact. could be confirmed.

Evaluation Example 4. SEM-EDX mapping analysis

SEM-EDX mapping analysis of the potassium ion exchanged CPFR of Preparation Examples 2 and 3 was performed in a known manner using a HITACHI S-4800 instrument. As a result, it was confirmed that K2CO3-CPFR and KOH-CPFR exhibited uniform potassium ion distribution as shown in Figures 21a and 21b, respectively.

Evaluation Example 5. Inductively coupled plasma-atomic emission spectroscopic analysis

Inductively coupled plasma-atomic emission spectroscopy analysis of the potassium ion exchanged CPFRs of Preparation Examples 2 and 3 was performed in a known manner using IPC-AES equipment (OPTIMA 7300 DV, Perkin-Elmer). As a result, it was confirmed that the K2CO3-CPFR beads of Preparation Example 2 and the KOH-CPFR beads of Preparation Example 3 had potassium of 1.7 wt% and 5.5 wt%, respectively.

Evaluation Example 6. N2 adsorption isotherm and BET specific surface area

To confirm the BET specific surface area of the beads of Preparation Examples 1 to 3, N2 adsorption isotherm was measured at 77K.

First, each of the beads of Preparation Examples 1 to 3 was activated at a temperature of 150°C under vacuum for 10 hours. Afterwards, the N2 adsorption isotherm according to P/P0 was derived as shown in Figure 25 using the BELSORP MAX instrument.

As a result, the PFR of Preparation Example 1 (black) shows a Brunauer-Emmett-Teller (BET) type I isotherm, indicative of a typical microporous material, while the K2CO3-CPFR of Preparation Example 2 (blue) and Preparation Example 3 KOH-CPFR (red) showed a slightly different isotherm type.

Meanwhile, the BET specific surface areas calculated through this were as shown in Table 1.

That is, while the PFR of Preparation Example 1 and the KOH-CPFR of Preparation Example 3 show a similar level of specific surface area, the K2CO3-CPFR of Preparation Example 2 has a specific surface area that is about 1.6 times higher than these.

Evaluation Example 7. NLDFT (Nonlocal Density Functional Theory)

The pore size distribution of the beads of Preparation Examples 1 to 3 was confirmed through the NLDFT method. As a result, a graph as shown in Figure 22 was derived (the inset image shows the distribution of fine pores with a diameter of less than 2 nm, W means the diameter of the pore, and dVp means the surface area).

Through this, the PFR beads (black) of Preparation Example 1 have only micropores, while the K2CO3-CPFR beads (blue) of Preparation Example 2 have micropores and mesopores, and the KOH-CPFR beads of Preparation Example 3 (red) It was confirmed that it had micro-pores, meso-pores, and macro-pores.

In other words, it was confirmed that KOH-CPFR beads with excessive potassium cation content mostly had macropores, while K2CO3-CPFR beads with adequate potassium cation content had micropores and mesopores, resulting in high surface area and total pore volume. (See Table 1 above and Table 2 below).

(Micropore size was estimated by NLDFT analysis based on slit-type carbon surface, and micropore volume was estimated by t-plot analysis)

Evaluation Example 8. Transmission electron microscope (TEM)

Preparation Example 2 TEM images of the beads were derived using a FEI Tecnai G2 F30 S-TWIN instrument.

As a result, it was confirmed that interconnected micropores and mesopores formed a hierarchical porous carbon network, as shown in Figure 23.

Evaluation Example 9. Raman Spectroscopy

Raman spectra for the beads of Preparation Examples 1 to 3 were measured using a LabRAM HR-800 spectrophotometer.

By determining the intensity of inelasticly scattered light and the amount of energy lost through the Raman peak distribution, it was possible to determine the defect concentration, that is, the amorphous nature of the target material. As a result of the measurement, as shown in Figure 24a, the (001) plane of graphite in the 2θ≒20°~30° region and the (101) plane diffraction peak in the 42°~43° region appeared, showing that Preparation Examples 1 to 2 It was found that the bead of 3 had the characteristics of amorphous carbon.

In addition, as shown in Figure 24b, it was found that all beads of Preparation Examples 1 to 3 had two distinct peaks at 1350 and 1580 cm-1, corresponding to the D and G bands. The D/G intensity ratios of Preparation Examples 1 to 3 are shown in Table 3 below. That is, it was confirmed that the potassium cation exchanged CPFR beads (K2CO3-CPFR beads and KOH-CPFR beads of Preparation Examples 2 and 3) had a high D/G ratio due to defect sites generated by the reaction of carbon and potassium cations, respectively ( The KOH-CPFR beads of Preparation Example 3, which had the highest K+ exchange content, had the highest D/G ratio).

Preparation Example 4. LVO (Li ₃ VO ₄ ) synthesis

0.234 g of ammonium metavanadate (Sigma Aldrich, 99%) and 0.245 g of lithium hydroxide monohydrate (JUNSEI, 98%) were added to 10 ml of deionized water and stirred for 15 minutes to obtain a homogeneous solution. Afterwards, 20 ml of methanol (Samchun, 99%) was added to the solution and stirred until it became a pale white solution. Then, the stirred solution was transferred to a 50 ml Teflon-lined autoclave, heated at 180°C for 4 hours, and then cooled to room temperature. The white precipitate that precipitated after cooling was washed three times with methanol (Samchun, 99%) and dried at 80°C under vacuum overnight. Subsequently, it was sintered at 500°C for 2 hours in an air atmosphere to obtain dried white powder (LVO powder).

Preparation Example 5. LVP (Li ₃ V ₂ (PO ₄ ) ₃ ) synthesis

LVP was prepared by a conventional solid phase reaction at high temperature.

First, lithium carbonate (Sigma-Aldrich, ≥99.0%), vanadium pentoxide (Alfa Aesar, 99%) and ammonium dihydrogen phosphate (Supelco, 99%) powder were mixed in a ratio of 3:2:6 (lithium carbonate:vanadium pentoxide:ammonium dihydrogen phosphate). The mixture was mixed at a molar ratio of and appropriately ground using an agate mortar until the powder turned yellow. Next, it was transferred to a porcelain crucible and sintered at a temperature of 300°C in an air atmosphere for 3 hours. Afterwards, the obtained product was pulverized again and sintered at a temperature of 850°C for 10 hours in a mixed gas atmosphere of H2 and Ar. Then, it was cooled to room temperature to obtain bright green LVP powder.

Preparation Example 6. Synthesis of LVO/K2CO3-CPFR nanocomposite

In preparation, 3 mg of LVO of 4 was dispersed in 50 ml of ethanol and sonicated for 30 minutes. Meanwhile, 27 mg of K2CO3-treated CPFR beads of Preparation Example 2 were dispersed in 10 ml of ethanol and transferred to a hot plate (watch glass stored at 80°C). Then, the LVO solution was added to the K2CO3-treated CPFR beads using a micropipette. After being added dropwise, it was dried overnight at a temperature of 80° C. Afterwards, the obtained dried powder was uniformly ground to obtain LVO/K2CO3-CPFR nanocomposite.

Preparation Example 7. Synthesis of LVO/KOH-CPFR nanocomposite

It was prepared in the same manner as Preparation Example 6, except that KOH (Samjeon Chemical, 95.0%) was used instead of K2CO3. As a result, LVO/KOH-CPFR nanocomposite was obtained.

Preparation Example 8. Formation of LVP/K2CO3-CPFR nanocomposite

It was prepared in the same manner as Preparation Example 6, except that LVP of Preparation Example 5 was used instead of LVO of Preparation Example 4. As a result, LVP/K2CO3-CPFR nanocomposite was obtained.

Preparation Example 9. Formation of LVP/KOH-CPFR nanocomposite

It was prepared in the same manner as Preparation Example 7, except that LVP of Preparation Example 5 was used instead of LVO of Preparation Example 4. As a result, LVP/KOH-CPFR nanocomposite was obtained.

Evaluation Example 10. X-ray diffraction analysis (XRD)

XRD patterns were recorded from 0 to 80 degrees at 0.1 degree intervals using a Rigaku MiniFlex 600 diffractometer with an operating wavelength of 1.51 Å.

As a result, graphs such as Figures 8 and 10 were derived.

Specifically, the K2CO3-CPFR beads (black) of Preparation Example 2 showed broad peaks at 24 deg and 44 deg, respectively, indexing the (200) and (101) planes of the carbon nanomaterial (the peak coincides with graphitic carbon). showing almost no amorphous properties) (see black graphs in Figures 8 and 10).

According to Figures 8 and 10, it was found that loading LVO or LVP into CPFR beads did not change the crystallinity, crystal structure, and lattice parameters.

Example 1.

Preparation of anode electrode

An anode electrode was manufactured using the LVO / K2CO3-CPFR nanocomposite of Preparation Example 6 as an anode active material.

First, 50 to 100 μL of n-methyl-2 was added to a mixture of 80% by weight of the active material, 10% by weight of Super-P (Sigma Aldrich, 99%), and 10% by weight of polyvinylidene fluoride (PVDF, Sigma Aldrich, 99%). -pyrrolidone (NMP, Sigma Aldrich, 99%) was added to form a uniform slurry, which was sonicated for 60 minutes.

Meanwhile, Cu foil (25 mm) with an area of 1 cm ² was prepared by washing it with ethanol to make the surface smooth and clean. Subsequently, the slurry was coated on Cu foil to a thickness of 25 to 35 mm using a doctor blade. Then, the coated foil was dried at room temperature overnight and then dried again in a vacuum at 100°C for 4 hours to prepare an anode electrode.

Preparation of cathode electrode

The cathode electrode was manufactured in the same manner as the anode electrode except that the LVP / K2CO3-CPFR nanocomposite of Preparation Example 8 was used as the active material and Al foil (25 mm) with an area of 1 cm ² was used as the current collector. did.

Manufacturing of coin cells

A coin cell was manufactured in a known manner by sequentially stacking an anode electrode, a separator, and a cathode electrode, and then injecting an electrolyte. The coin cell manufacturing was performed in a glove box in an Ar atmosphere containing 0 to 0.2 ppm of oxygen and 0 ppm of hydrogen.

At this time, the slurry layer of the anode electrode and the slurry layer of the cathode electrode were arranged to face each other. Meanwhile, a glass fiber separator (Whatman, thickness 790 mm, diameter 90 mm) was used as the separator, and an electrolyte prepared by adding 1.0 M LiPF6 to an EMC/DMC solvent was used.

Comparative Example 1.

Preparation of anode electrode

In preparation, 3 mg of LVO of 4 was dispersed in 50 ml of ethanol and sonicated for 30 minutes. Meanwhile, 27 mg of Super-P was dispersed in 10 ml of ethanol and transferred to a hot plate (watch glass stored at 80°C). Then, the LVO solution was added dropwise to Super-P using a micropipette, and then incubated at a temperature of 80°C. After drying overnight, the obtained dried powder was ground uniformly to obtain LVO/Super-P composite.

50 to 200 μL of n-methyl-2-pyrrolidone in a mixture of 80% by weight of active material, 10% by weight of Super-P (Sigma Aldrich, 99%), and 10% by weight of polyvinylidene fluoride (PVDF, Sigma Aldrich, 99%). (NMP, Sigma Aldrich, 99%) was added to form a uniform slurry, which was sonicated for 60 minutes.

Meanwhile, Cu foil (25 mm) with an area of 1 cm ² was prepared by washing it with ethanol to make the surface smooth and clean. Subsequently, the slurry was coated on Cu foil to a thickness of 25 to 35 mm using a doctor blade. Then, the coated foil was dried at room temperature overnight and then dried again in a vacuum at 100°C for 4 hours to prepare an anode electrode.

Preparation of cathode electrode

A cathode electrode was manufactured in the same manner as Comparative Example 1, except that the LVP of Preparation Example 5 was used as the cathode active material.

Manufacturing of coin cells

A coin cell was manufactured in the same manner as in Example 1, except that the anode electrode and cathode electrode were used as above.

Evaluation Example 11. Cyclic Voltammetry (CV)

Cyclic voltammetry was performed using WonA Tech's WMPG1000 potentiostat. The coin cell was measured in a voltage range of 0 to 3V, and the measurement temperature was 25°C.

Figure 12 is a CV curve measured at different scan speeds for the coin cell of Example 1. As shown in FIG. 12, it was confirmed that the coin cell of Example 1 exhibited a quasi-rectangular profile with a redox peak near 2.25 V. Through this, it can be seen that the electrochemical properties are further improved in the case of a coin cell containing LVO/K2CO3-CPFR nanocomposite as an anode active material and LVP/K2CO3-CPFR nanocomposite as cathode active material.

Meanwhile, Figure 13 is a graph comparing the CV of Example 1 and Comparative Example 1. Accordingly, it was found that the electrode manufactured according to Example 1 had a higher electrochemical capacity than the electrode of Comparative Example 1.

Evaluation example 12. Galvanostat charge/discharge characteristics

The galvanostat charge/discharge characteristics were performed in a known manner using WonA Tech's WMPG1000 and varying the current density.

As a result, the results shown in Figure 14 were obtained.

The following facts could be clearly understood through the charge/discharge curve of FIG. 14.

(i) The nonlinearity of the charge/discharge flat surface indicates that the charge accumulation process is carried out by capacitive and Faradaic processes.

(ii) The charge/discharge curve does not start at the appropriate potential (slightly outside 0 V and 3 V) and may result from IR drop and the internal resistance of the cell.

(iii) The charge curve shows a larger electric capacity than the discharge curve, which is presumed to result from the growth of a solid electrolyte interfacial layer (SEI layer) at low current densities. At this time, the discharge capacity of the cell is estimated to be about 84.8 mAh/g at a current density of 1A g ^-1 .

Meanwhile, as a result of analyzing rate characteristics according to current density, it was confirmed that capacity was maintained even after crossing between high and low current densities. Additionally, as a result of a charge/discharge stability experiment conducted at a current density of 2A/g, no performance degradation was observed even after 225 cycles.

In addition, as a result of calculating the energy and power density based on the discharge time and capacity obtained above, the energy density was 127 Wh/kg and the power density was 14.3 kW/kg.

Evaluation example 13. Rate Capability characteristics

For coin cells, charging and discharging characteristics were evaluated at various C-rates using WonA Tech's WMPG1000.

As a result, as shown in FIG. 15, it was confirmed that the discharge capacity was 86.7, 51.07, 33.13, and 22.72 mAh g ^-1 for each of the five cycle sections at rates of 1, 2, 3, and 4C.

Claims (14)

A composite of hierarchical carbon particles and LVO (LVO/C composite); or a composite of hierarchical carbon particles and LVP (LVP/C composite);
The composite of the hierarchical carbon particles and LVO (LVO/C composite) is an electrode active material, characterized in that it contains the carbon particles in the range of 500 to 9500 parts by weight based on 100 parts by weight of the LVO. delete The electrode active material of claim 1, wherein the composite of hierarchical carbon particles and LVP (LVP/C composite) includes the hierarchical carbon particles in the range of 500 to 9500 parts by weight based on 100 parts by weight of the LVP.
According to claim 1,
The hierarchical carbon particles include an inlet with a size ranging from 1 nm to 500 nm on the surface that can enter internal pores, and at least two types of macro pores, meso pores, and micro pores on the inside. Contains more pores,
The hierarchical carbon particles form a hierarchical porous carbon network in which at least two types of pores among the macro pores, meso pores, and micro pores are interconnected.
The electrode active material according to claim 1, wherein the hierarchical carbon particles are obtained by ion-exchanging a hydroxyl group-containing resin with potassium cations (K+) and carbonizing it.
◈Claim 6 was abandoned upon payment of the setup registration fee.◈ The electrode active material according to claim 5, wherein the hydroxyl group-containing resin is Phenol Formaldehyde Resin.
According to claim 1,
According to Raman spectroscopy, it exhibits a D band peak within a wavelength range of 1300 to 1400 cm-1, a G band peak within a wavelength range of 1550 to 1620 cm-1, and the intensity ratio of the D band to the G band ( An electrode active material containing carbon particles, characterized in that D/G) is 0.7 to 1.5.
The electrode active material according to claim 1, comprising hierarchical carbon particles having a BET specific surface area of 830 m2/g or more.
The electrode active material according to claim 1, comprising hierarchical carbon particles having a total pore volume of 0.4 cm3/g or more.
The electrode active material according to claim 1, wherein the average size of the micro pores is in the range of 0.7 to 2.0 nm, and the micro pore volume is 0.35 to 1.5 cm3/g.
◈Claim 11 was abandoned upon payment of the setup registration fee.◈ The electrode active material according to claim 1, comprising hierarchical carbon particles having a spherical bead shape.
A composite of hierarchical carbon particles and LVO (LVO/C composite); or a composite of hierarchical carbon particles and LVP (LVP/C composite); Contains at least one of the following,
The composite of the hierarchical carbon particles and LVO (LVO/C composite) is a capacitor, characterized in that it contains the carbon particles in the range of 500 to 9500 parts by weight with respect to 100 parts by weight of the LVO. delete The capacitor of claim 12, wherein the capacitor has a power density of 10 kW/kh or more and an energy density of 90 Wh/kg or more.