KR20200111299A - Mesoporous carbon/Lithium titanium oxide composite anode for lithium battery - Google Patents

Abstract

The present invention relates to a composite electrode for a lithium secondary battery containing mesoporous carbon and lithium titanium oxide nanoflakes.

Description

Composite electrode for lithium secondary battery containing mesoporous carbon/lithium titanium oxide nanoflakes (MC/LTO-NF) {Mesoporous carbon/Lithium titanium oxide composite anode for lithium battery}

The present invention relates to a composite electrode for a lithium secondary battery comprising mesoporous carbon and lithium titanium oxide nanoflakes.

As the electric, electronic, telecommunication and computer industries have rapidly developed, the demand for high-performance and high-stability secondary batteries has gradually increased. Particularly, secondary batteries, which are key parts of this field, have been made in line with the trend of miniaturization and portability of precision electrical products. The battery is also required to be lighter and smaller. In response to such a demand, one of the batteries that has received the most attention recently is a lithium secondary battery.

The lithium secondary battery is generally largely composed of a positive electrode, a negative electrode, an electrolyte, and a separator, and among them, a negative active material used as a negative electrode material is one of the configurations that have the greatest influence on the performance of a lithium secondary battery.

Patent No. 10-450548 provides a negative electrode active material including a first layer containing carbon as a main component and a second layer of a lithium storage material having an amorphous structure in order to improve battery efficiency while maintaining high charge/discharge efficiency and excellent cycle characteristics. have. However, since the above patent uses carbon as a main component, it has a disadvantage that the high output characteristics of the battery are very low.

Patent No. 10-796687 discloses an active material selected from among Si and Sn, oxides thereof, tin alloy composites, lithium metal nitride and lithium metal oxide in order to exhibit excellent life characteristics and high conductivity even when a small amount of conductive material is used. , A negative electrode active material for a lithium secondary battery including a carbon conductive material on its surface is provided. However, the above method has a complicated process and has an economic problem due to the use of high temperature heat treatment, silicon or tin, and the like.

Accordingly, there is a need for a negative electrode material for a lithium secondary battery, which not only has excellent high capacity and high output characteristics, but also has improved life stability according to cycles.

1. Korean Patent Publication No. 10-450548 2. Korean Patent Publication No. 10-796687

An object of the present invention is to provide a negative electrode composite electrode for a lithium secondary battery that has excellent high capacity and high output characteristics and has improved life stability according to cycles. Specifically, charge/discharge capacity and electrical conductivity are improved, as well as lifespan depending on the number of cycles. It is to provide a negative electrode composite electrode for a lithium secondary battery with significantly improved stability.

The present invention includes lithium titanium oxide and mesoporous carbon,

The lithium titanium oxide provides a composite electrode for a lithium secondary battery that satisfies the following Formula 1.

[Formula 1]

Li _x Ti _y O _z

(In Formula 1, 0.5≦x≦5, 1≦y≦5, and 2≦z≦12)

In one embodiment according to the present invention, the mesoporous carbon may have a specific surface area of 800 to 3000 m ² /g.

In an embodiment according to the present invention, the mesoporous carbon includes mesopores, and in the total pore volume, which is the volume of total pores per unit mass, the fraction occupied by the mesopore volume, which is the volume of mesopores per unit mass, is 5 to It can be 80%.

In an embodiment according to the present invention, the mesoporous carbon may have an average pore size of 1 to 20 nm.

In one embodiment according to the present invention, the lithium titanium oxide may have a plate-shaped nanoflake shape.

In an embodiment according to the present invention, the nanoflakes may have an average long axis length and a thickness ratio of 20 to 500 in the plane direction.

In an embodiment according to the present invention, one or more conductive materials selected from carbon black, graphite, and graphene may be further included.

In one embodiment according to the present invention, one or two or more binders selected from a fluorine-based polymer, an acrylic polymer, an epoxy-based polymer, and a cellulose-based polymer may be further included.

In one embodiment according to the present invention, the weight ratio of the lithium titanium oxide and the mesoporous carbon may be 1:0.1 to 1:10.

In an embodiment according to the present invention, the conductive material may include 1 to 100 parts by weight based on 100 parts by weight of mesoporous carbon.

The present invention

a) mixing a lithium precursor and a titanium precursor;

b) obtaining lithium titanium oxide powder from the mixture;

c) calcining the obtained lithium titanium oxide to obtain lithium titanium oxide nanoflakes;

d) preparing a slurry containing the obtained lithium titanium oxide nanoflakes and mesoporous carbon; And

e) coating the slurry on a current collector; and a method for manufacturing a composite electrode for a lithium secondary battery comprising:

In an embodiment according to the present invention, in step c), the calcination may be performed at 500 to 1000°C.

In an embodiment of the present invention, in step d), the slurry may further include a conductive material and a binder.

In one embodiment according to the present invention, the lithium precursor in step a) is lithium hydroxide, lithium hydroxide monohydrate, lithium chloride, lithium acetate, lithium acetate dihydrate, lithium sulfate, lithium sulfate monohydrate, It may be one or more selected from the group consisting of lithium phosphate, lithium nitrate, and salts thereof.

In an embodiment according to the present invention, the titanium precursor in step a) is titanium (IV) tetramethoxide, titanium (IV) tetraethoxide, titanium (IV) tetrapropoxide, titanium (IV) tetraiso It may be one or more selected from the group consisting of proposide, titanium (IV) tetrabutoxide, titanium (IV) tetraisobutoxide, titanium (IV) tetrapentoxide, titanium (IV) tetraisopentoxide, and salts thereof. .

The present invention also provides a lithium secondary battery including a composite electrode for a lithium secondary battery manufactured according to an embodiment of the present invention.

The composite electrode for a lithium secondary battery according to an embodiment of the present invention has excellent high capacity and high output characteristics, and has an advantage of improving life stability according to cycles.

1 shows a graph comparing impedance spectra of a composite electrode after 600 cycle tests of a coin cell manufactured using the composite electrode of Example 1, Comparative Example 1, and Comparative Example 2 of the present invention.
Figure 2 shows the result of the characteristic evaluation using the cyclic voltammetry method of a coin cell manufactured using the composite electrode of Example 1 of the present invention.
3 shows the result of characteristic evaluation using the cyclic voltammetry method of a coin cell manufactured using the composite electrode of Comparative Example 1 of the present invention.
Figure 4 shows the result of the characteristic evaluation using the cyclic voltammetry method of a coin cell manufactured using the composite electrode of Comparative Example 2 of the present invention.
FIG. 5 shows a scanning electron microscope photograph of a composite electrode after 600 cycle test of a coin cell manufactured using the composite electrode of Example 1 of the present invention.

Unless otherwise defined, technical terms and scientific terms used in the present specification have the meanings commonly understood by those of ordinary skill in the art to which this invention belongs, and the gist of the present invention in the following description and accompanying drawings A description of known functions and configurations that may unnecessarily obscure will be omitted.

The present invention includes lithium titanium oxide and mesoporous carbon,

The lithium titanium oxide provides a composite electrode for a lithium secondary battery that satisfies the following Formula 1.

[Formula 1]

Li _x Ti _y O _z

(In Formula 1, 0.5≦x≦5, 1≦y≦5, and 2≦z≦12)

The composite electrode for a lithium secondary battery according to the present invention includes lithium titanium oxide and mesoporous carbon, thereby having an advantage of exhibiting high capacity and high output characteristics.

Specifically, the composite electrode for a lithium secondary battery according to the present invention has the formula Li _x Ti _y O _z (0.5 ≤ x ≤ 5, 1 ≤ y ≤ 5 and 2 ≤ _z ≤ 12, preferably 1 ≤ x ≤ 4, 2 ≤ y By including lithium titanium oxide and mesoporous carbon having ≤ 5 and 5 ≤ z ≤ 12), electrical conductivity can be remarkably improved to show high output, and a solid electrolyte interface (SEI) generated during charging and discharging High capacity can be achieved by remarkably reducing problems such as layer formation, electrode volume change, and lithium precipitation.

In the composite electrode for a lithium secondary battery according to an embodiment of the present invention, the mesoporous carbon has a specific surface area of 800 to 3000 m ² /g, preferably 1000 to 2500 m ² /g, more preferably 1200 to 2300 m ² / can be g By increasing the surface area per unit volume within the above range, an additional electron transfer path can be formed, thereby exhibiting high electrical conductivity. In addition, the capacity and output of the lithium secondary battery can be greatly improved by uniformly maintaining the current and voltage distribution in the electrode during charging and discharging.

In the composite electrode for a lithium secondary battery according to an embodiment of the present invention, the mesoporous carbon includes mesopores, and in the total pore volume, which is the volume of total pores per unit mass, the mesopore volume, which is the volume of mesopores per unit mass, is The fraction occupied may be 5 to 80%, preferably 40 to 70%, but is not limited thereto. In the mesopore fraction range, the charging capacity can be increased during charging and discharging, and at the same time, the discharge capacity can also be increased.

In addition, according to the definition of IUPAC, when pores smaller than 2 nm in diameter are referred to as micro pores, pores having a diameter of 2 nm to 50 nm are referred to as mesopores, and pores of 50 nm or more are referred to as macro pores, lithium according to an embodiment of the present invention In the composite electrode for a secondary battery, the mesoporous carbon may have an average pore size of 1 to 20 nm, more preferably 2 to 15 nm. By maintaining excellent strength within the above range, deformation and oxidation of the surface of the current collector can be prevented even under conditions such as repeated charge/discharge and overcharge, thereby exhibiting high performance.

In the composite electrode for a lithium secondary battery according to an embodiment of the present invention, the lithium titanium oxide may have a plate-shaped nanoflake shape. When the lithium titanium oxide has a nanoflake shape, it is advantageous because it can greatly improve the cycle characteristics of the composite electrode. In detail, when the lithium titanium oxide is in the form of nanoflakes, it may have excellent cycle characteristics that hardly cause a decrease in capacity and an increase in resistance even during repeated charging and discharging of 500 or more times. The nanoflakes may have an average long axis length and a thickness in a plane direction (average long axis length/thickness in a plane direction) of 20 to 500, preferably 30 to 400, more preferably 50 to 350, but are not limited thereto. Specifically, the nanoflakes are not greatly limited, but the average long axis length in the plane direction may be 5 to 30 μm, more preferably 6 to 26 μm. Within the above range, lithium titanium oxide nanoflakes and mesoporous carbon can be uniformly mixed, and furthermore, even when coating on a current collector, they can be distributed in a uniform thickness over a large area, so that long-term cycle characteristics can be further improved. .

In the composite electrode for a lithium secondary battery according to an embodiment of the present invention, the weight ratio of the lithium titanium oxide and the mesoporous carbon may be 1:0.1 to 1:10, more preferably 1:0.3 to 1:5, but is limited thereto. I don't. Within the above range, lithium titanium oxide and the mesoporous carbon may be uniformly mixed, and the current collector may be uniformly coated, so that electrical conductivity may be remarkably improved.

The composite electrode for a lithium secondary battery includes a current collector; And an active material layer positioned on at least one surface of the current collector, and the active material layer may include the above-described lithium titanium oxide and mesoporous carbon, and may further include a conductive material and/or a binder. .

The conductive material may further include one or two or more selected from carbon black, graphite, and graphene. The conductive material may include 1 to 100 parts by weight, preferably 5 to 50 parts by weight, and more preferably 12 to 35 parts by weight, based on 100 parts by weight of the mesoporous carbon, but is not limited thereto. Preferably, by further including the carbon-based conductive material, sufficient electrical contact with mesoporous carbon having a large specific surface area may be achieved, and high electrical conductivity may be exhibited through this.

The binder may further include one or more selected from a fluorine-based polymer, an acrylic polymer, an epoxy-based polymer, and a cellulose-based polymer. Specifically, polyvinylidene fluoride (PVdF), polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropyl cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene- It may be one or two or more selected from diene triple polymer (EPDM), sulfonated EPDM, styrene butadiene rubber and fluorine rubber, but is not limited thereto. The binder may include 1 to 100 parts by weight, preferably 5 to 50 parts by weight, and more preferably 12 to 35 parts by weight, based on 100 parts by weight of the mesoporous carbon, but is not limited thereto.

The current collector is not particularly limited as long as it has conductivity without causing chemical change, and for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, and the like may be used. In addition, the current collector has a thickness of 3 to 500 μm, preferably 50 to 300 μm, which is advantageous for electrical conductivity.

The present invention also,

a) mixing a lithium precursor and a titanium precursor;

b) obtaining lithium titanium oxide powder from the mixture;

c) calcining the obtained lithium titanium oxide to obtain lithium titanium oxide nanoflakes;

d) preparing a slurry containing the obtained lithium titanium oxide nanoflakes and mesoporous carbon; And

e) coating the slurry on a current collector; and a method for manufacturing a composite electrode for a lithium secondary battery comprising:

The manufacturing method of the composite electrode for a lithium secondary battery according to the present invention comprises the step of preparing a lithium titanium oxide nanoflake, the step of preparing a slurry containing the obtained lithium titanium oxide nanoflake and mesoporous carbon, and has high capacity and high output characteristics. Not only this is excellent, but also has the advantage of obtaining a composite electrode for a lithium secondary battery that can improve the life stability according to a long-term charge/discharge cycle.

In the method of manufacturing a composite electrode for a lithium secondary battery according to the present invention, steps a) and b) include mixing a lithium precursor and a titanium precursor to obtain a lithium titanium oxide powder. Specifically, after preparing the lithium precursor solution and the titanium precursor solution, they are put into an autoclave container to perform heat treatment, followed by washing and drying to obtain lithium titanium oxide powder. It is much more advantageous for reactivity to perform the heat treatment at 100 to 300°C, more preferably at 120 to 200°C for 10 to 30 hours, more preferably 15 to 28 hours. The mixing molar ratio of the lithium precursor and the titanium precursor may be 1 to 0.5 to 1 to 30, but is not limited thereto. In addition, the concentration of the lithium precursor and the titanium precursor may be 0.01 to 50 mol/l, specifically 0.05 to 10 mol/l, and more specifically 0.1 to 1 mol/l, but this is only an example and is not limited thereto.

The lithium precursor is the group consisting of lithium hydroxide, lithium hydroxide monohydrate, lithium chloride, lithium acetate, lithium acetate dihydrate, lithium sulfate, lithium sulfate monohydrate, lithium phosphate, lithium nitrate, and salts thereof. It may be one or more selected from, but is not limited thereto. In addition, the titanium precursor is titanium (IV) tetramethoxide, titanium (IV) tetraethoxide, titanium (IV) tetrapropoxide, titanium (IV) tetraisopropoxide, titanium (IV) tetrabutoxide, titanium (IV) ) Tetraisobutoxide, titanium (IV) tetrapentoxide, titanium (IV) tetraisopentoxide, and salts thereof may be one or more selected from the group consisting of, but is not limited thereto.

The precursor is dissolved in a solvent to form a solution, and the solution may be obtained by a solvent selected from water, alcohol, ketone, weak acid, amide, or a mixture thereof, but is not limited thereto.

In the method of manufacturing a composite electrode for a lithium secondary battery according to an embodiment of the present invention, the calcination in step c) may be performed at 500 to 1000°C, preferably 550 to 900°C, and more preferably 600 to 800°C. The calcination is a step of converting the lithium titanium oxide powder obtained through the steps a) and b) into lithium titanium oxide nanoflakes, preferably 2 to 10 hours, more preferably 4 to 8 hours in the temperature range. It is possible to obtain a more uniform nanoflake-shaped lithium titanium oxide. Accordingly, lithium titanium oxide nanoflakes and mesoporous carbon can be uniformly mixed, and furthermore, even when coated on a current collector, they can be distributed in a uniform thickness over a large area, thereby improving the life stability according to a long charging and discharging cycle. It has the advantage of being able to.

In the method of manufacturing a composite electrode for a lithium secondary battery according to an embodiment of the present invention, the slurry in step d) may further include a conductive material and a binder. The method of preparing the slurry is not limited, but may be uniformly mixed using a ball mill. Specifically, it may be performed at 100 to 1000 rpm, more preferably at 250 to 400 rpm, and is not limited thereto, but may be performed for 1 to 3 hours, specifically 1 to 2 hours.

If the conductive material is one or two or more selected from carbon black, graphite, and graphene, it is not particularly limited. In addition, if the binder is one or two or more selected from a fluorine-based polymer, an acrylic polymer, an epoxy-based polymer, and a cellulose-based polymer, it is not particularly limited. The conductive material and the binder may include 1 to 100 parts by weight, preferably 5 to 50 parts by weight, and more preferably 12 to 35 parts by weight, respectively, based on 100 parts by weight of the mesoporous carbon, but are not limited thereto. The mesoporous carbon may be included in 20 to 60 parts by weight, specifically 30 to 50 parts by weight, based on 100 parts by weight of the slurry.

As a dispersion solvent in the slurry, a solvent selected from N-methyl-2-pyrrolidone (NMP), dimethylformamide, dimethylacetamide, N,N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran, etc. may be used. , But is not limited thereto.

In the method of manufacturing a composite electrode for a lithium secondary battery according to the present invention, step e) includes coating a slurry including lithium titanium oxide nanoflakes and mesoporous carbon on a current collector. Specifically, the coating may be performed by doctor blade, immersion, brushing, or the like, but is not limited thereto.

The present invention also provides a lithium secondary battery including a composite electrode for a lithium secondary battery manufactured according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail through examples, but these are for explaining the present invention in more detail, and the scope of the present invention is not limited by the following examples.

Titanium (IV) tetrabutoxide was added to an ethanol solvent to prepare a titanium precursor solution having a concentration of 0.5 mol/L, followed by sufficiently stirring. Subsequently, after preparing a lithium precursor solution having a concentration of 0.4 mol/L prepared by adding lithium hydroxide to distilled water, the titanium precursor solution and the lithium precursor solution were mixed so as to have a weight ratio of 1:0.8, and then sufficiently stirred for 1 hour. I did. Then, heat treatment was performed at 180° C. for 24 hours in an autoclave, washed twice with distilled water and once with ethanol, and dried at 60° C. for one or more days to obtain lithium titanium oxide powder. The obtained lithium titanium oxide powder was calcined at 600° C. for 6 hours to obtain lithium titanium oxide nanoflakes. After mixing the lithium titanium oxide nanoflakes and mesoporous carbon (UniAM) having a specific surface area of 1454 m ² /g, a mesopore fraction of 30% and an average pore size of 3.5 nm in a ratio of 1 to 1 part by weight, mesoporous carbon With respect to 100 parts by weight, 20 parts by weight of carbon black and 20 parts by weight of PVdF were dissolved in N-methyl-2-pyrrolididone (NMP) to prepare a slurry. The slurry was coated on a copper foil current collector having a thickness of 100 μm to a thickness of 65 μm with a doctor blade, followed by drying and rolling to prepare a composite electrode.

In Example 1, except that the titanium precursor solution and the lithium precursor solution were mixed in a weight ratio of 1:2, and lithium titanium oxide nanoflakes obtained through the same step and mesoporous carbon were mixed in an amount of 1 to 3.2 parts by weight. It carried out in the same manner as in Example 1.

In Example 1, lithium titanium oxide nanoflakes and mesoporous carbon were mixed in an amount of 1 to 1 parts by weight, and then, based on 100 parts by weight of mesoporous carbon, 25 parts by weight of PVdF was added to N-methyl-2-pyrrolidone (NMP). It was carried out in the same manner as in Example 1, except that the slurry was prepared by dissolving.

(Comparative Example 1)

It was carried out in the same manner as in Example 1, except that mesoporous carbon was not added.

(Comparative Example 2)

Except for not adding lithium titanium oxide nanoflakes in Example 1, it was carried out in the same manner.

(Experimental Example 1)

<Evaluation of battery characteristics>

Using the composite electrode of Example 1 and Comparative Examples 1 to 2 as a working electrode, and a lithium metal as a counter electrode, a coin cell with a diameter of 14 mm was manufactured. At this time, a separator made of a porous polypropylene film is inserted between the working electrode and the counter electrode, and as an electrolyte, a mixture of diethyl carbonate (DEC) and ethylene carbonate (EC) is 1:1 in a mixed solution having a concentration of 1M. What dissolved LiPF ₆ was used. Table 1 shows the results of evaluating the battery characteristics at a current density of 500 mA/g using the prepared coin cell.

1 ^st cycle discharge capacity (mAh/g) 600 ^th cycle charging capacity (mAh/g) 1 ^st cycle
Discharge average voltage Example 1 250 225 3.76 Comparative Example 1 180 160 3.74 Comparative Example 2 150 120 3.72

As can be seen in Table 1, the discharge capacity of a lithium secondary battery including a composite electrode containing lithium titanium oxide nanoflakes and mesoporous carbon is the highest, and a lithium secondary battery that uses lithium titanium oxide or does not contain mesoporous carbon In the case of, it can be seen that not only the discharge capacity is relatively low, but also the discharge capacity decreases after 600 cycles. That is, it can be seen that the high capacity characteristics of the lithium secondary battery including the composite electrode according to the present invention and the life stability according to the cycle are improved. In addition, it can be seen that the high output characteristics are also improved because the average discharge voltage of the lithium secondary battery including the composite electrode manufactured according to the present invention is the highest. (Experimental Example 2)

<Impedance evaluation>

In Experimental Example 1, impedance was measured in the frequency range of 10 mHz to 100 kHz for the composite electrodes of Example 1 and Comparative Examples 1 to 2 after 600 cycle characteristics were evaluated, and the experimental results are shown in FIG.

As can be seen from FIG. 1, after the 600 cycle charge/discharge test, it can be seen that the composite electrode of Example 1 exhibited lower resistance than Comparative Examples 1 and 2. Specifically, in the impedance graph, since the diameter of a large circle represents the charge transfer resistance, the smaller the diameter, the smaller the resistance and the better electrochemical properties. As can be seen in FIG. 1, the composite electrode according to the present invention exhibited a resistance of 19.3 ohm after 600 cycles of charging and discharging, but Comparative Example 1 exhibited 24.7 ohm and Comparative Example 2 exhibited 29.5 ohm. In addition, while going to a lower frequency, it was found that the slope of the Warburg impedance of Example 1 was larger than that of Comparative Example 2, and it could be seen that the mass transfer resistance was also significantly reduced. That is, it can be seen that the stability in terms of electrochemical properties of the composite electrode according to the present invention is improved.

[Experimental Example 3]

< Cyclic voltammetry Analysis>

Including the composite electrode of Example 1 and Comparative Examples 1 to 2, and using a coin cell manufactured in the same manner as in Experimental Example 1, the electrochemical properties were evaluated using a cyclic voltammetry method for each scan speed in the range of 0.01 to 3 V. And the results are shown in FIGS. 2 to 4.

As can be seen from Figures 2 to 4, it can be seen that the composite electrode according to Example 1 exhibits reversibility as well as much better electrochemical reactivity than Comparative Examples 1 and 2.

[Experimental Example 4]

< SEM Analysis>

In Experimental Example 1, a scanning electron microscope photograph was taken of the composite electrode of Example 1 after 600 cycle characteristics were evaluated, and the results are shown in FIG. 5.

As can be seen in Figure 5, it can be seen that even after 600 cycles of charging and discharging, lithium titanium oxide nanoflakes and mesoporous carbon are uniformly distributed.

Claims (16)

Including lithium titanium oxide and mesoporous carbon,
The lithium titanium oxide is a composite electrode for a lithium secondary battery that satisfies the following Formula 1.
[Formula 1]
Li _x Ti _y O _z
(In Formula 1, 0.5≦x≦5, 1≦y≦5, and 2≦z≦12) The method of claim 1,
The mesoporous carbon is a composite electrode for a lithium secondary battery that has a specific surface area of 800 to 3000 m ² /g. The method of claim 1,
The mesoporous carbon includes mesopores, and in the total pore volume, which is the volume of total pores per unit mass, the fraction occupied by the mesopore volume, which is the mesopore volume per unit mass, is 5 to 80% . The method of claim 3,
The mesoporous carbon is a composite electrode for a lithium secondary battery having an average pore size of 1 to 20 nm. The method of claim 1,
The lithium titanium oxide is a composite electrode for a lithium secondary battery having a plate-shaped nanoflake shape. The method of claim 5,
The nanoflake is a composite electrode for a lithium secondary battery in which the ratio of the average long axis length and thickness in the plane direction is 20 to 500. The method of claim 1,
A composite electrode for a lithium secondary battery further comprising one or more conductive materials selected from carbon black, graphite, and graphene. The method of claim 1,
A composite electrode for a lithium secondary battery further comprising one or two or more binders selected from a fluorine-based polymer, an acrylic polymer, an epoxy-based polymer, and a cellulose-based polymer. The method of claim 1,
The weight ratio of the lithium titanium oxide and the mesoporous carbon is 1:0.1 to 1:10, the composite electrode for a lithium secondary battery. The method of claim 7,
The conductive material is a composite electrode for a lithium secondary battery containing 1 to 100 parts by weight based on 100 parts by weight of mesoporous carbon. a) mixing a lithium precursor and a titanium precursor;
b) obtaining lithium titanium oxide powder from the mixture;
c) calcining the obtained lithium titanium oxide to obtain lithium titanium oxide nanoflakes;
d) preparing a slurry containing the obtained lithium titanium oxide nanoflakes and mesoporous carbon; And
e) coating the slurry on a current collector; a method of manufacturing a composite electrode for a lithium secondary battery comprising. The method of claim 10,
In the step c), the calcination is carried out at 500 to 1000 ℃ method of manufacturing a composite electrode for a lithium secondary battery. The method of claim 10,
In step d), the slurry further includes a conductive material and a binder. The method of claim 10,
In the step a), the lithium precursor is lithium hydroxide, lithium hydroxide monohydrate, lithium chloride, lithium acetate, lithium acetate dihydrate, lithium sulfate, lithium sulfate monohydrate, lithium phosphate, lithium nitrate, and salts thereof. A method of manufacturing a composite electrode for a lithium secondary battery that is at least one selected from the group consisting of. The method of claim 10,
In the step a), the titanium precursor is titanium (IV) tetramethoxide, titanium (IV) tetraethoxide, titanium (IV) tetrapropoxide, titanium (IV) tetraisopropoxide, titanium (IV) tetrabutoxide. , Titanium (IV) tetraisobutoxide, titanium (IV) tetrapentoxide, titanium (IV) tetraisopentoxide, and a method of producing a composite electrode for a lithium secondary battery that is at least one selected from the group consisting of a salt thereof. A lithium secondary battery comprising a composite electrode for a lithium secondary battery manufactured by the method of manufacturing a composite electrode for a lithium secondary battery according to any one of claims 10 to 14.

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