KR102453094B1 - Method for preparing hybrid composite prepared from ti based metal-organic framework - Google Patents

Abstract

Disclosed are a method for preparing a hybrid composite including lithium titanate (LTO) and a carbon material prepared through a reduction reaction of a Ti-based metal-organic framework (MOF), and a hybrid composite prepared according to the method. Since the hybrid composite has high porosity and excellent electrical conductivity, it is possible to improve energy density and output characteristics of the device when it is used in electrodes such as supercapacitors or secondary batteries.

Description

Method for producing a hybrid composite prepared from a Ti-based metal-organic framework

The present invention relates to a method for preparing a hybrid composite comprising lithium titanate (LTO) and a carbon material prepared through a reduction reaction of a Ti-based metal-organic framework (MOF) and a hybrid composite prepared according to the method it's about

A super-capacitor is a capacitor with a very large capacitance, and is called an ultra-capacitor or ultra-high-capacitance capacitor in Korean. In scientific terms, it is called an electrochemical capacitor to distinguish it from the conventional electrostatic or electrolytic capacitors. Unlike a battery that uses a chemical reaction, a supercapacitor uses a simple movement of ions to the electrode and electrolyte interface or a charging phenomenon by a surface chemical reaction. As a result, rapid charge/discharge is possible, and due to its high charge/discharge efficiency and semi-permanent cycle life characteristics, it is in the spotlight as a next-generation energy storage device that can be used as a substitute for an auxiliary battery or a battery.

Supercapacitors have been commercialized since the 1980s and have a relatively short history of development, but their development is due to the development of hybrid-type product design technology using asymmetric electrodes and new electrode materials such as metal oxides and conductive polymers, including activated carbon, which have been traditionally used. The speed is very fast. Recently announced products have energy density that exceeds that of Ni-MH batteries.

Supercapacitors, a next-generation energy storage device, can quickly store and take out a large amount of electricity, have 100 times higher output than secondary batteries, and can be used semi-permanently, so there are various application fields such as mobile phones, digital camera flashes, and hybrid vehicles. do. In other words, supercapacitors are important as renewable energy storage devices such as solar power, wind power, and hydrogen fuel cells, which are eco-friendly, clean alternative energy that does not emit carbon dioxide by replacing petroleum.

However, in the case of supercapacitors developed so far, carbon-based electrode materials mainly store energy in the electric double layer, so they have relatively high output characteristics, but have low energy storage. Although it has the advantage of high storage capacity, it has many problems such as the disadvantage that it is difficult to use in mass production because the material is expensive. Therefore, in order to improve the energy density and power density of the supercapacitor, it is urgent to develop an electrode having high porosity and electrical conductivity, which is inexpensive and has high electrical conductivity.

Meanwhile, a hybrid capacitor that has been recently studied is a capacitor that combines the power storage principle of a lithium ion secondary battery and a supercapacitor. The hybrid capacitor has no volume change when lithium ions are removed/inserted into the negative electrode, can be charged/discharged at high speed, and has a long cycle repetition characteristic of 50,000 or more lithium titanate (LTO) or lithium vanadium oxide (LVO) and a positive electrode It has more than twice the energy density of the existing electric double layer capacitor (EDLC) by combining activated carbon with it.

However, lithium titanate (LTO) or lithium vanadium oxide (LVO) used as an anode active material can improve energy density due to structural stability and a fast lithium diffusion rate, but due to the nature of the metal oxide, electrical conductivity is low, so it can be used as an electrode. There is a problem in that the output characteristics are reduced because the resistance of the cell is increased.

Accordingly, the present inventors prepared a hybrid composite by reducing a conventional titanium (Ti)-based metal-organic framework with a lithium precursor and heat-treating it while researching to solve the above problems, and this is a supercapacitor or secondary battery When applied as an electrode of the hybrid composite, it was confirmed that the performance of a supercapacitor or a secondary battery can be improved due to the characteristic high porosity and electrical conductivity characteristics of the hybrid composite, thereby completing the present invention. On the other hand, the hybrid complex is applied in various fields, such as a catalyst for water purification, an anticancer agent, an immunodeficiency virus treatment, a treatment for fungal and bacterial infections, a treatment for malaria, various drug delivery materials, photocatalysts, sensors, and aerospace materials, in addition to supercapacitors or secondary batteries. As this is possible, it can be used as a commercially very useful material.

In this regard, Korean Patent Registration No. 10-1639206 discloses a method for preparing a negative electrode slurry composition including a dispersion mixture of graphite and LTO coated with a conductive material.

The present invention has been devised to solve the above problems, and an embodiment of the present invention provides a method for preparing a hybrid composite prepared through a reduction reaction of a Ti-based metal-organic framework (MOF).

In addition, another embodiment of the present invention provides a hybrid composite prepared according to the method for preparing the hybrid composite.

In addition, another embodiment of the present invention provides an electrode active material including the hybrid composite.

However, the technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned are clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. it could be

As a technical means for achieving the above-described technical problem, one aspect of the present invention is,

reducing the Ti-based metal-organic framework (MOF) using a lithium precursor; and heat-treating the reduced Ti-based metal-organic framework.

The Ti-based metal-organic framework is MIL-125, NH ₂ -MIL-125, ZTOF-1, ZTOF-2, CTOF-1, CTOF-2, NTU-9, PCN-22, COK-69, MIL- It may include a material selected from the group consisting of 101(Ti), MOF-901, MIL-167, MIL-168, MIL-169, MOF-902, and combinations thereof.

The lithium precursor may include a monovalent lithium cation.

The lithium precursor may include an anion selected from the group consisting of a butyl group, an alkoxide group, acetate, carbonate, halide, amidinate, diketonate, and combinations thereof.

The step of reducing the Ti-based metal-organic framework (MOF) using a lithium precursor; may be a reduction treatment by adding an excess of lithium precursor.

The reducing step; may be characterized in that the reduction by further mixing a carbon material in addition to the Ti-based metal-organic framework.

The carbon material is activated carbon (activated carbon), carbon nanotube (CNT), graphene oxide (graphene oxide, GO), reduced graphene oxide (reduced graphene oxide, rGO), carbon fiber (carbon fiber), It may include a material selected from the group consisting of graphite and combinations thereof.

The content of the carbon material may be 0.01 parts by weight to 50 parts by weight based on 100 parts by weight of the Ti-based metal-organic framework.

The heat treatment may be performed at a temperature of 300 °C to 700 °C.

The heat treatment may be performed for 8 to 16 hours.

In addition, another aspect of the present invention,

It provides a hybrid composite prepared according to the method for preparing the hybrid composite.

The hybrid composite may be characterized in that it has a spinel structure.

The hybrid composite may have a BET specific surface area of 10 m ² /g to 2,000 m ² /g.

The total pore volume of the hybrid composite may be 0.02 cm ³ /g to 1.0 cm ³ /g.

The micropore volume of the hybrid composite may be 0.001 cm ³ /g to 0.5 cm ³ /g.

The mesopore volume of the hybrid composite may be 0.01 cm ³ /g to 0.5 cm ³ /g.

According to an embodiment of the present invention, since the hybrid composite has high porosity and excellent electrical conductivity, it is possible to improve the energy density and output characteristics of the device when using it for an electrode such as a supercapacitor or a secondary battery.

In addition, since the hybrid composite is prepared by simply reducing the Ti-based metal-organic framework using a lithium precursor and heat-treating it, it is a relatively easy method compared to the conventional manufacturing method that includes the step of additionally mixing a carbon material. A hybrid composite including lithium titanate (LTO) and a carbon material may be manufactured. That is, as described above, since manufacturing is relatively easy, mass production is possible, and thus it may be highly useful industrially.

The effects of the present invention are not limited to the above effects, and it should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a schematic diagram showing a manufacturing process of a hybrid composite according to an embodiment of the present invention.
Figure 2 shows the X-ray diffraction pattern of the hybrid composite powder prepared according to an embodiment of the present invention; (Left) (a) MIL-125 simulation values and (b) MIL-125 actually prepared (right) (a) lithiated MIL-125 (MIL-125 treated with a lithium precursor) and (b) 500°C, (c) 600° C., (d) 700° C., and (e) 800° C. show samples that were heat treated in a nitrogen atmosphere for 2 hours.
3 is a scanning electron microscope (FE-SEM) data; (a) actually prepared MIL-125 (right) (b) lithiated MIL-125 (MIL-125 treated with a lithium precursor) and (c) 500°C, (d) 600°C, (e) 700°C, (f) shows samples that were heat treated for 2 hours in a nitrogen atmosphere at different temperatures of 800 °C.
4 is XRD data of a hybrid composite prepared according to another embodiment of the present invention.
Figure 5 shows the nitrogen adsorption and desorption curves of the hybrid composite prepared according to an embodiment of the present invention: (a) 600 ℃, (b) 700 ℃, and (c) 800 ℃.
6 is an Elemental mapping of a hybrid composite prepared according to an embodiment of the present invention: shows Ti and C elements of a 700 °C sample.
7 is a transmission electron microscope image of the hybrid composite prepared according to an embodiment of the present invention, (top) MIL-125, (bottom) 700 ℃ heat treatment sample.
8 is a graph showing the charge and discharge capacity when the hybrid composite prepared according to an embodiment of the present invention is used as an electrode material, and the sample is a 700° C. heat treatment sample.
9 is a graph of discharge capacity for each C-rate for safety evaluation when the hybrid composite prepared according to an embodiment of the present invention is used as an electrode material, and the sample is a 700 ^o C heat treatment sample.
10 is data for evaluating the electrochemical performance of a hybrid capacitor using the hybrid composite prepared according to an embodiment of the present invention as an electrode material.

Hereinafter, the present invention will be described in more detail. However, the present invention may be embodied in various different forms, and the present invention is not limited by the embodiments described herein, and the present invention is only defined by the claims to be described later.

In addition, the terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the entire specification of the present invention, 'including' any component means that other components may be further included, rather than excluding other components, unless otherwise stated.

The first aspect of the present application is

reducing the Ti-based metal-organic framework (MOF) using a lithium precursor; and heat-treating the reduced Ti-based metal-organic framework.

Hereinafter, the method for preparing the hybrid composite according to the first aspect of the present application will be described in detail step by step with reference to FIG. 1 . 1 is a schematic diagram showing a manufacturing process of a hybrid composite according to an embodiment of the present invention.

First, in one embodiment of the present application, the method for preparing the hybrid composite includes: reducing a Ti-based metal-organic framework (MOF) using a lithium precursor.

In one embodiment of the present application, the Ti-based metal-organic framework (MOF) refers to a metal-organic framework including Ti as a metal, for example, MIL-125, NH2-MIL-125, ZTOF-1, ZTOF-2, CTOF-1, CTOF-2, NTU-9, PCN-22, COK-69, MIL-101(Ti), MOF-901, MIL-167, MIL-168, MIL-169 , may include a material selected from the group consisting of MOF-902 and combinations thereof, and may preferably be MIL-125. That is, Ti included in the metal-organic framework may be a titanium source of a hybrid composite to be prepared later.

In one embodiment of the present application, the lithium precursor may be a material containing a monovalent lithium cation, (hydroxyl group,) butyl group, alkoxide group, acetate, carbonate, halide, amidinate, diketonate and an anion selected from the group consisting of combinations thereof. Preferably, in one embodiment of the present application, the lithium precursor may be n-butyllithium (n-BuLi). That is, the anion included in the lithium precursor may reduce the Ti-based metal-organic framework, and the monovalent lithium cation may be a lithium source (Li source) of the hybrid composite to be prepared later. Meanwhile, the lithium precursor may be dissolved in a solvent. In this case, the type of the solvent is not particularly limited, but may be an organic solvent, preferably hexane. In this case, preferably, the concentration of the lithium precursor may be 1 to 10 M, for example, about 2.5 M, and the reduction reaction may be performed for about 4 days.

In one embodiment of the present application, the step of reducing the Ti-based metal-organic framework (MOF) using a lithium precursor; Based on 100 parts by weight of the Ti-based metal-organic framework, it may be preferably 100 parts by weight or more, and more preferably 200 parts by weight or more. When the content of the lithium precursor is too small compared to the Ti-based metal-organic framework, the content of the lithium precursor is relatively small, so the reduction reaction of the metal-organic framework may not be smoothly performed. On the other hand, when the content of the lithium precursor is excessive compared to the Ti-based metal-organic framework, a sufficient reduction reaction may occur and the residual lithium may improve charge/discharge capacity.

In one embodiment of the present application, the reducing step; may be characterized in that the reduction by further mixing a carbon material in addition to the Ti-based metal-organic framework. In this case, the carbon material is activated carbon (activated carbon), carbon nanotube (CNT), graphene oxide (graphene oxide, GO), reduced graphene oxide (reduced graphene oxide, rGO), carbon fiber (carbon fiber) ), graphite, and may include a material selected from the group consisting of combinations thereof, and preferably, the carbon material may be a carbon nanotube (CNT).

In one embodiment of the present application, the content of the carbon material may be 0.01 parts by weight to 50 parts by weight, preferably 0.1 parts by weight to 40 parts by weight, based on 100 parts by weight of the Ti-based metal-organic framework, More preferably, it may be 1 part by weight to 30 parts by weight. When the content of the carbon material is less than 0.01 parts by weight compared to 100 parts by weight of the Ti-based metal-organic framework, the content of the carbon material is relatively small, so that the hybrid composite prepared thereafter may exhibit low electrical conductivity, and if it exceeds 50 parts by weight In this case, the content of the Ti-based metal-organic framework and the lithium precursor is relatively small, so that the hybrid composite prepared thereafter may exhibit low structural stability.

Next, in one embodiment of the present application, the method for preparing the hybrid composite includes the step of heat-treating the reduced Ti-based metal-organic framework.

In one embodiment of the present application, the method for preparing the hybrid composite may include washing the excess lithium precursor before heat-treating the reduced Ti-based metal-organic framework. That is, by washing the excess lithium precursor, the lithium precursor not participating in the reaction for preparing the hybrid composite may be removed. Meanwhile, a lithium titanate (LTO)/carbon material composite may be prepared by heat-treating the reduced Ti-based metal-organic framework. That is, the hybrid composite may refer to the lithium titanate (LTO)/carbon material composite. On the other hand, the heat treatment may be carried out at a temperature of 300 ° C to 700 ° C under a nitrogen or argon atmosphere, preferably at a temperature of 400 ° C to 600 ° C, more preferably at a temperature of about 500 ° C. it may be In addition, the heat treatment may be performed for 8 to 16 hours, preferably for about 12 hours. When the heat treatment is performed at a temperature of less than 300 ° C. or is carried out for less than 8 hours, the hybrid composite may not be smoothly prepared. It may be uneconomical because the temperature and time ranges for

The second aspect of the present application is

It provides a hybrid composite prepared according to the manufacturing method of the first aspect of the present application.

Although detailed descriptions of parts overlapping with the first aspect of the present application are omitted, the contents described with respect to the first aspect of the present application may be equally applied even if the description thereof is omitted in the second aspect.

Hereinafter, the hybrid complex according to the second aspect of the present application will be described in detail.

In one embodiment of the present application, the hybrid composite may include lithium titanate (LTO) and/or lithium titanate (LTO)/carbon material composite, wherein the hybrid composite has a spinel structure it could be

In one embodiment of the present application, the BET specific surface area of the hybrid composite may be 10 m ² /g to 2,000 m ² /g, preferably 20 m ² /g or more. On the other hand, the BET specific surface area may vary depending on the type of carbon material to be added. For example, when the carbon material is activated carbon, the BET specific surface area may be 10 m ² /g to 2,000 m ² /g. .

In one embodiment of the present application, the hybrid composite may have a porous structure, and specifically may include micropores and mesopores at the same time. In this case, the micropore volume of the hybrid composite may be 0.001 cm ³ /g to 0.5 cm ³ /g. In addition, the mesopore volume of the hybrid composite may be 0.01 cm ³ /g to 0.5 cm ³ /g. On the other hand, the micropore and mesopore volume of the hybrid composite may vary depending on the type of the added carbon material, for example, when the carbon material is activated carbon, the micropore volume is 0.001 cm ³ /g to 0.5 cm ³ It may be /g, and the mesopore volume may be 0.01 cm ³ /g to 0.5 cm ³ /g.

In one embodiment of the present application, the total pore volume of the hybrid composite may be defined as the sum of the micropore volume and the mesopore volume, and other pore volumes may be additionally included. Specifically, the total pore volume of the hybrid composite may be 0.02 cm ³ /g to 1.0 cm ³ /g, preferably 0.02 cm ³ /g to 0.5 cm ³ /g. On the other hand, the total pore volume of the hybrid composite may also vary depending on the type of the added carbon material, for example, when the carbon material is activated carbon, the total pore volume is 0.02 cm ³ /g to 1.0 cm ³ /g it could be

That is, since the hybrid composite has a high BET specific surface area and porosity, when it is used as an electrode active material of an electrochemical device such as a secondary battery or a supercapacitor, the occlusion and desorption of the electrolyte is easy, and the electrochemical properties of the electrochemical device are improved. may be improved.

In one embodiment of the present application, the electrical conductivity of the hybrid composite may be 0.01 S·cm ¹ or more. In this case, the electrical conductivity of the hybrid composite may be measurable in the form of polycrystalline pellets or polycrystalline films. According to an embodiment of the present application, the electrical conductivity of the hybrid composite pellets may be 0.01 S·cm ^-1 or more, preferably 0.01 S·cm ^-1 to 10 S·cm ^-1 , more preferably 1 S·cm -1 cm ^-1 to 5 S·cm ^-1 may be. In addition, the electrical conductivity of the hybrid composite film may be 10 S·cm ^-1 or more based on an average film thickness of 500 nm, preferably 0.01 S·cm ^-1 to 100 S·cm ^-1 , more preferably 0.01 S·cm ^-1 to 50 S·cm ^-1 may be.

The third aspect of the present application is

It provides an electrode active material comprising the hybrid composite according to the first and second aspects of the present application.

Although detailed descriptions of parts overlapping with the first and second aspects of the present application are omitted, the descriptions of the first and second aspects of the present application may be equally applied even if the description is omitted in the third aspect. .

Hereinafter, an electrode active material including the hybrid composite according to the third aspect of the present application will be described in detail.

In one embodiment of the present application, the electrode active material may be used in a secondary battery or a supercapacitor, etc., and since the hybrid composite has high porosity and excellent electrical conductivity, the energy density and output characteristics of the devices are improved. can Specifically, the BET specific surface area of the hybrid composite may be 10 m ² /g to 2,000 m ² /g, the total pore volume may be 0.02 cm ³ /g to 1.0 cm ³ /g, and the electrical conductivity is 0.01 S·cm ^-1 or more.

In one embodiment of the present application, the electrode active material may be formed on the electrode current collector. In this case, if the electrode current collector has conductivity without causing a chemical change of the device, there may be no restriction on the type of the current collector. For example, the electrode current collector may include stainless steel, aluminum, nickel, titanium, sintered carbon, or a material in which carbon, nickel, titanium, silver, or the like is surface-treated on the surface of aluminum or stainless steel. Meanwhile, the electrode current collector may have a thickness of about 3 μm to 500 μm, and may be to form fine irregularities on the surface of the current collector to increase the adhesion of the electrode active material. That is, it may be used in various forms, such as a film, a sheet, a foil, a net, a porous body, a foam, a nonwoven body, and the like.

In one embodiment of the present application, the electrode active material may further include a conductive material and a binder in addition to the active material. In this case, the conductive material is used to impart conductivity to the electrode, and as long as it has electrical conductivity without causing a chemical change in the device, there may be no restriction on the type of the conductive material. For example, the conductive material may include graphite such as natural graphite or artificial graphite, carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, summer black, carbon-based materials such as carbon fiber, copper, nickel aluminum , a metal powder or metal fiber such as silver, a conductive whiskey such as zinc oxide and potassium titanate, a conductive metal oxide such as titanium oxide or a conductive polymer such as a polyphenylene derivative, and a material selected from the group consisting of combinations thereof may be doing Meanwhile, the conductive material may be typically used in an amount of 1 to 30 parts by weight based on 100 parts by weight of the electrode active material.

In addition, the binder may serve to improve adhesion between the electrode active material particles and adhesion between the electrode active material and the current collector. Specifically, the binder is, for example, polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile (polyacrylonitrile), Carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), alcohol It may include a material selected from the group consisting of ponylated-EPDM, styrene butadiene rubber (SBR), fluororubber, or various copolymers thereof and combinations thereof. Meanwhile, the binder may be typically used in an amount of 1 to 30 parts by weight based on 100 parts by weight of the electrode active material.

In addition, the supercapacitor may preferably be a hybrid supercapacitor, and the hybrid supercapacitor may specifically include a positive electrode; cathode; It may include a separator and an electrolyte interposed between the positive electrode and the negative electrode. In this case, the electrode active material may preferably be one used as the active material of the negative electrode, and activated carbon may be used as the positive electrode active material of the positive electrode.

In one embodiment of the present application, the electrolyte used in the hybrid supercapacitor may be used by mixing a salt and an additive in an organic solvent. At this time, the organic solvent is ACN (Acetonitrile), EC (Ethylene carbonate), PC (Propylene carbonate), DMC (Dimethyl carbonate), DEC (Diethyl carbonate), EMC (Ethylmethyl carbonate), DME (1,2-dimethoxyethane), It may include a material selected from the group consisting of GBL (γ-buthrolactone), MF (Methyl formate), MP (Methyl propionate), and combinations thereof. In addition, 0.8 to 2 M of the salt is used, and a lithium (Li) salt and a non-lithium salt may be mixed and used. The lithium (Li) salt is accompanied by an insertion/desorption reaction into the structure of the anode active material, that is, the metal-organic framework, and its types include LiBF ₄ , LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiAlCl ₄ , LiCF ₃ SO ₃ , LiN(SO ₂ CF ₃ ) ₂ , LiC(SO ₂ CF ₃ ) ₃ , LiBOB (Lithium bis(oxalato)borate), and combinations thereof may be included. In addition, the non-lithium salt is accompanied by an adsorption/desorption reaction on the surface area of the carbon material additive, and may be used by mixing 0 to 0.5 M with the lithium salt. In this case, the non-lithium salt contains a material selected from the group consisting of TEABF ₄ (Tetraethylammonium tetrafluoroborate), TEMABF ₄ (Triethylmethylammonium tetrafluorborate), SBPBF ₄ (spiro-(1,1′)-bipyrrolidium tetrafluoroborate) and combinations thereof. may be doing In addition, the carbon material additive may include a material selected from the group consisting of VC (Vinylene Carbonate), VEC (Vinyl ethylene carbonate), FEC (Fluoroethylene carbonate), and combinations thereof.

In one embodiment of the present application, the separator is positioned between the positive electrode and the negative electrode to prevent the positive electrode and the negative electrode from being in physical contact with each other to prevent an electrical short, and a material having a porosity may be used. For example, the separator may include a material selected from the group consisting of polypropylene-based, polyethylene-based, polyolefin-based, and combinations thereof.

In one embodiment of the present application, the hybrid supercapacitor having the above configuration has high electrical conductivity because the hybrid composite is used as the negative electrode active material, and the capacity is improved due to the high specific surface area to have high energy density and output characteristics. have. That is, since the hybrid composite includes lithium titanate (LTO) and a carbon material, a hybrid supercapacitor including the same may exhibit excellent electrical conductivity, capacitance, and output characteristics.

In one embodiment of the present application, the hybrid complex is a catalyst for water purification in addition to the electrode active material of a supercapacitor or secondary battery, an anticancer agent, an immunodeficiency virus treatment agent, a treatment agent for fungal and bacterial infections, a treatment agent for malaria, various drug delivery materials, a photocatalyst, a sensor, Since it can be applied in various fields such as aerospace materials, it can be used as a commercially very useful material.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.

Example 1. Preparation of hybrid complex (using MIL-125 alone)

In order to prepare a hybrid complex according to the present invention, first, 0.3 g of MIL-125 (Ti) was treated with 5 ml of 2.5 M n-BuLi dissolved in hexane (excessive input) and reacted for 4 days to react with MIL-125. (Ti) was reduced. Thereafter, excess Li was washed, and a hybrid composite (LTO/C) was prepared by heat treatment at a temperature of 500° C. under a nitrogen atmosphere for 12 hours. The manufacturing process of the hybrid composite is briefly shown in FIG. 1 . Then, samples that were heat-treated for 2 hours in a nitrogen atmosphere at different temperatures of 500 °C, 600 °C, 700 °C, and 800 °C were prepared, respectively.

Example 2. Preparation of hybrid composite (addition of carbon nanotubes)

A hybrid composite was prepared in the same manner as in Example 1, except that n-BuLi was treated by additionally mixing 0.03 g of multi-walled carbon nanotubes (MCNT) in addition to MIL-125 (Ti).

Experimental Example 1. Surface analysis of hybrid complex

In order to analyze the surface of the hybrid complex, Figure 3 is a scanning electron microscope (FE-SEM) data; (a) MIL-125 actually prepared (right) (b) MIL-125 treated with a lithium precursor and (c) different temperatures of 500°C, (d) 600°C, (e) 700°C, (f) 800°C The samples were heat-treated for 2 hours in a nitrogen atmosphere. As shown in FIG. 3 , it was confirmed that the hybrid complex was smoothly formed, and it was confirmed that it contained particles having a size of about 10 nm to 50 nm.

Experimental Example 2. XRD analysis of hybrid complex

XRD analysis of the hybrid complex prepared in Example 1 was performed, and the results are shown in FIG. 2 . In addition, XRD analysis of the hybrid complex prepared in Example 2 was performed, and the results are shown in FIG. 4 . As shown in FIGS. 2 and 4 , the peaks of the hybrid composites prepared in Examples 1 and 2 coincided with the theoretically appearing LTO crystallinity peaks, confirming that the hybrid composites contained LTO. In addition, it was confirmed that the hybrid composite had a spinel structure.

Figure 2 shows the X-ray diffraction pattern of the hybrid composite powder prepared according to an embodiment of the present invention; (Left) (a) MIL-125 simulation value and (b) MIL-125 actually prepared (right) (a) MIL-125 treated with a lithium precursor and (b) 500°C, (c) 600°C, (d) ) 700 ℃, (e) shows the samples heat-treated for 2 hours in a nitrogen atmosphere at different temperatures of 800 ℃. Referring to FIG. 2 , even when the heat treatment temperature is increased, the main peaks are included the same, and it can be seen that the peak intensity increases as the temperature increases.

Experimental Example 3. Nitrogen adsorption/desorption analysis of hybrid complex

Figure 5 shows the nitrogen adsorption and desorption curves of the hybrid composite prepared according to an embodiment of the present invention: (a) 600 ℃, (b) 700 ℃, and (c) 800 ℃.

According to FIG. 5 , it was observed that the adsorption amount of nitrogen decreased as the heat treatment temperature increased. These results indicate that as the heat treatment temperature increases, the total pore volume and specific surface area decrease.

Experimental Example 4. Elemental Mapping Analysis of Hybrid Composite

6 is an Elemental mapping of a hybrid composite prepared according to an embodiment of the present invention: shows Ti and C elements of a 700 °C sample.

According to FIG. 6 , it was observed that Ti and C were evenly distributed and formed on the surface of the hybrid composite of the present invention.

Experimental Example 5. Transmission electron microscope analysis of hybrid complex

7 is a transmission electron microscope image of the hybrid composite prepared according to an embodiment of the present invention, (top) MIL-125, (bottom) 700 ℃ heat treatment sample.

According to FIG. 7 , it was confirmed that the composite particle structure was formed through the shape of the transmitted particles, rather than when only MIL-125 was observed.

Experimental Example 4. Electrochemical Characterization of Hybrid Composite

8 is a graph showing the charge and discharge capacity when using the hybrid composite prepared according to an embodiment of the present invention as an electrode material, the samples are 600 ℃, 700 ℃, 800 ℃ heat treatment samples, 9 is a graph of discharge capacity by C-rate for safety evaluation when the hybrid composite prepared according to an embodiment of the present invention is used as an electrode material, the sample is a 700 ^o C heat treatment sample, and FIG. It is data evaluating the electrochemical performance of a hybrid capacitor using the hybrid composite prepared according to an embodiment of the present invention as an electrode material.

According to the results of FIGS. 8 to 10 , it can be confirmed that when the hybrid composite of the present invention is used as an electrode material, it can be utilized as an excellent material in terms of capacity characteristics, stability, capacitance, current density, and the like.

Claims (16)

reducing the Ti-based metal-organic framework (MOF) using n-BuLi; and
Including; heat-treating the reduced Ti-based metal-organic framework;
The reducing step is a method for producing a core-shell type composite, characterized in that the reduction by further mixing a carbon material in addition to the Ti-based metal-organic framework.
According to claim 1,
The Ti-based metal-organic framework is MIL-125, NH ₂ -MIL-125, ZTOF-1, ZTOF-2, CTOF-1, CTOF-2, NTU-9, PCN-22, COK-69, MIL- 101(Ti), MOF-901, MIL-167, MIL-168, MIL-169, MOF-902, and a method for producing a composite comprising a material selected from the group consisting of combinations thereof.
delete delete delete delete According to claim 1,
The carbon material is activated carbon (activated carbon), carbon nanotube (CNT), graphene oxide (graphene oxide, GO), reduced graphene oxide (reduced graphene oxide, rGO), carbon fiber (carbon fiber), A method for producing a composite comprising a material selected from the group consisting of graphite and combinations thereof.
According to claim 1,
The content of the carbon material is 0.01 parts by weight to 50 parts by weight based on 100 parts by weight of the Ti-based metal-organic framework.
According to claim 1,
The heat treatment is a method of manufacturing a composite that is performed at a temperature of 300 ℃ to 700 ℃.
According to claim 1,
The heat treatment is a method for producing a composite that is performed for 8 to 16 hours.
A core-shell type composite prepared according to the method of claim 1 .
12. The method of claim 11,
The composite is characterized in that it has a spinel (spinel) structure.
12. The method of claim 11,
The complex has a BET specific surface area of 10 m ² /g to 2,000 m ² /g.
12. The method of claim 11,
The composite has a total pore volume of 0.02 cm ³ /g to 1.0 cm ³ /g.
◈Claim 15 was abandoned when paying the registration fee.◈ 12. The method of claim 11,
The complex has a micropore volume of 0.001 cm ³ /g to 0.5 cm ³ /g.
◈Claim 16 has been abandoned at the time of payment of the registration fee.◈ 12. The method of claim 11,
The mesopore volume of the composite is 0.01 cm ³ /g to 0.5 cm ³ /g of the composite.

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