KR101914557B1 - Methods of preparing lithium titanium oxide for providing lithium secondary batteries with enhanced properties and lithium secondary batteries containing the same - Google Patents

Abstract

Disclosure of the Invention The present invention provides a lithium ion secondary battery capable of producing a high-density electrode when using lithium titanium oxide as an electrode material for providing a high capacity lithium secondary battery, It is about the method.
Specifically, in the present invention, a titanium compound structure having a high density structure is prepared from a titanium compound to be a raw material of lithium titanium oxide and used for the production of lithium titanium oxide, whereby a high density electrode active material . Further, the present invention can achieve miniaturization of a high capacity electrode and a battery by using the electrode active material.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a lithium secondary battery, and more particularly, to a lithium secondary battery having improved lithium secondary batteries,

The present invention relates to a method for producing lithium titanium oxide as an electrode material material for providing a high-density and high-capacity lithium secondary battery.

In addition, the present invention provides a high capacity and miniaturized lithium secondary battery.

With the rapid development of the electronics, communications and computer industries, portable electronic communication devices such as camcorders, mobile phones and notebook PCs are making remarkable progress. Accordingly, the demand for lithium secondary batteries as power sources capable of driving them has been increasing day by day. In particular, research and development are being actively carried out in Japan, Europe, and the United States, as well as domestic applications for applications such as electric vehicles, uninterruptible power supplies, power tools and satellites as eco-friendly power sources.

Currently, lithium metal and carbon are used as anode active materials for lithium secondary batteries. When lithium metal is used as a negative electrode active material, it is very likely that dendrite crystals are formed on the surface of the electrode by repeating a charge / discharge cycle, resulting in a short circuit and a low safety. On the other hand, as the carbon material, crystalline carbon such as natural graphite, artificial graphite, non-graphitizable carbon, amorphous carbon such as graphitizable carbon and the like are used. However, the carbon material has a problem of high irreversibility and low initial discharge efficiency and a decrease in capacity. When overcharged, lithium is precipitated on the carbon surface, which may cause safety problems.

In recent years, studies on lithium titanium oxide (Li ₄ Ti ₅ O ₁₂ , LTO) as a material that can overcome such problems have been actively conducted. LTO is an electrode active material with a stable structure of spinel structure. Its operating voltage is relatively high at 1.3 ~ 1.6V and the theoretical capacity is as small as 175mAh / g. However, irreversible reaction does not exist (initial efficiency is over 95% There is no volume change during charging and discharging, and it is advantageous in that it is very safe because the amount of heat generated is small. In addition, lithium titanium oxide can withstand cyclic charging and discharging reactions over a long period of time without degradation of battery characteristics, due to a unique small volume change during charging and discharging processes.

On the other hand, the carbon material has a theoretical density as low as 2 g / cm ³ , but the LTO is as high as 3.5 g / cm ^3, so the capacity per volume is similar to that of carbon. When an active material is actually applied to an electrode, the capacity per volume is more important than the capacity per mass. Therefore, providing LTO that can improve the capacity per volume is important in terms of improving the characteristics of the lithium secondary battery.

Therefore, it is important to develop lithium titanium oxide that can improve the capacity per unit volume by increasing the electrode density when it is made into an electrode of a lithium secondary battery.

An object of the present invention is to provide a lithium titanium oxide which can increase the electrode density when used as an electrode material of a lithium secondary battery and improve the charge / discharge capacity of the battery.

The present invention also aims to achieve miniaturization of a lithium secondary battery using lithium titanium oxide as an electrode material.

The present invention relates to a lithium titanium oxide (Li ₄ Ti ₅ O ₁₂ , Li ₄ Ti ₅ O ₁₂ , Li ₄ Ti ₅ O ₁₂ , LTO). ≪ / RTI >

Preferably, the titanium compound structure is produced by pulverizing, drying and heat-treating the titanium compound.

Preferably, the heat treatment is performed at a temperature of 700 ° C to 900 ° C for 1 to 4 hours.

Preferably, the titanium compound is selected from the group comprising TiO ₂ , TiH ₂ , TiCl ₄ , TiN, C ₁₂ H ₂₈ O ₄ Ti, and combinations thereof.

Preferably, the lithium compound is selected from the group consisting of Li ₂ CO ₃ , LiOH, LiNO ₃ , Li ₂ C ₂ O ₄ , Li ₃ PO ₄ , Li ₂ HPO ₄ , LiHCO ₃ , LiOOCCH ₃ , LiVO ₃ And combinations thereof.

Preferably, the slurry of the lithium compound may be aqueous or nonaqueous.

Preferably, the reaction product obtained from the reaction of the lithium compound slurry with the titanium compound structure is calcined at a temperature of 700 ° C to 900 ° C for 10 to 20 hours.

Also, the present invention provides an electrode for a lithium secondary battery comprising the lithium titanium oxide produced by the above production method, and a lithium secondary battery.

In the electrode including the lithium-titanium oxide of the present invention, the density of the electrode is improved.

Further, in the lithium secondary battery using the lithium titanium oxide of the present invention as an electrode material, the capacity of the battery is increased.

Therefore, according to the present invention, miniaturization of the lithium secondary battery can be achieved.

FIG. 1 shows a structural change in the process of forming a conventional lithium titanium oxide.
Fig. 2 shows the structural change during the formation of the lithium titanium oxide of the present invention.
3 is an SEM photograph of the lithium titanium oxide produced in Example 1. Fig.
4 is a SEM photograph of the lithium titanium oxide produced in Comparative Example 1. FIG.

The present invention relates to a lithium secondary battery which is a means for providing a high capacity lithium secondary battery with a high capacity by achieving an electrode density and a high capacity in an electrode manufactured using lithium titanium oxide as an electrode material, (Li ₄ Ti ₅ O ₁₂ , LTO), which is characterized by controlling the density and the density of the lithium titanium oxide.

Specifically, the present invention relates to a method for producing lithium titanium oxide (LTO), which comprises the steps of preparing a titanium compound structure whose structure and density are controlled from a titanium compound, and reacting the titanium compound structure with a lithium compound slurry . That is, in the present invention, it is intended to provide a lithium titanium oxide which can be used for the production of a high-density electrode therefrom by previously controlling the titanium compound as a raw material of lithium titanium oxide to have a dense dense structure.

As shown in FIG. 1, in the conventional process of producing lithium titanium oxide, lithium is completely melted and diffused into a liquid phase by a heat treatment to be described later. At this time, lithium lithium is melted and diffused as a titanium element, The space of the lithium becomes vacant, so that a lot of pore structure is included therein. However, in the present invention, as shown in FIG. 2, a titanium compound structure (solidly formed of titanium particles) prepared in a dense structure is used as a raw material, and diffusion of lithium occurs on the surface thereof. Therefore, fusion and diffusion The structure of the titanium compound structure is maintained without being destroyed. That is, a lithium titanium oxide having a solid structure can be obtained.

In the present invention, lithium titanium oxide produced by using a titanium compound structure having a controlled structure with a high density can be produced by pelletizing at a predetermined pressure to produce pellets, or by pressing on an electrode plate to produce electrodes, And the results are shown in Fig. This is thought to be due to the fact that a pellet or an electrode plate is obtained in a state where the powder is compressed or the pores are efficiently filled at the time of pressing because the produced lithium titanium oxide contains few pores in the powder.

In the present invention, a step of pulverizing, drying and heat-treating is preferably carried out in order to control the structure and density of the titanium compound.

In the pulverizing step, the titanium compound in a slurry state may be pulverized with a bead mill to produce a pulverized titanium compound slurry, but the present invention is not limited thereto. The pulverization rate and time in the preparation of the titanium compound slurry are selected according to the type of beads, the size, and the kind and size of the titanium compound to be used. The finishing point is determined by D _max . In the present invention, when TiO ₂ is used as a titanium compound in one embodiment, pulverization is carried out until D _max becomes 3 μm.

Next, the powder in the pulverized slurry is dried. In the drying process, spray drying may be used, but the present invention is not limited thereto. It may also be dried by passing through a nozzle-type spray dryer, but is not limited thereto.

In the drying process, the structure and the density of the titanium compound may be changed according to the type of the dryer and the operation conditions, so that the dryer and the operating conditions are selected. For example, the shape of the titanium compound structure formed by the structure of the dryer differs. That is, depending on the design of the nozzle, it is determined whether the dried powder has a coarse structure or a dense structure, and the size and density of the dried structure vary depending on the nozzle pressure. Also, various parameters such as varying the density of the powder depending on the solids content of the slurry in the operating conditions affect the characteristics of the dried powder.

Next, a step of heat-treating the dried powder is performed. The heat treatment is performed at a temperature of 700 ° C to 900 ° C for 1 to 4 hours. The heat treatment may be performed in an atmosphere selected from the group consisting of a nitrogen gas, an argon gas, an argon / hydrogen mixed gas, and a nitrogen / hydrogen mixed gas, but may be performed in a normal atmospheric environment. The internal structure and density of the titanium compound in the heat treatment process are changed according to the heat treatment conditions. That is, as the annealing time increases, the internal density of the TiO ₂ structure increases. This is thought to be due to consisting of a TiO ₂ Necking between particles forming the TiO ₂ structure, with increasing the heat treatment time increases the internal density. These structural changes are more evident as the heat treatment temperature increases.

According to the present invention, by preparing lithium titanium oxide by reacting a structure prepared by pulverizing, drying and heat-treating a titanium compound as described above with a lithium compound, it is possible to provide a high-density lithium titanium oxide having a low pore structure therein have.

Specifically, the titanium compound structure is added to a slurry of a lithium compound to be reacted. The slurry of the lithium compound may be a water system using water as a solvent or a nonaqueous system using acetone, methanol, ethanol or isopropyl alcohol. That is, a lithium compound slurry is prepared from a solvent selected depending on whether the lithium compound is water-soluble or organic solvent-soluble.

In addition, in the above reaction, the solid content ratio of the solvent to the lithium compound and the titanium compound structure compound is preferably 10 to 40 wt% in the solvent.

After completion of the reaction between the lithium compound and the titanium compound structural compound in the solvent, the solvent is removed by spray drying, vacuum drying, atmospheric drying or oven drying or the like, whereby a powdery lithium titanium oxide mixture (two raw materials until the heat treatment, It is called a " lithium titanium mixture " in order to distinguish it from lithium titanium oxide).

The powdery lithium titanium mixture thus obtained is made into a final lithium titanium oxide for use as an electrode active material by heat treatment. The heat treatment proceeds by calcining at a temperature of 700 ° C to 900 ° C for 10 to 20 hours. When the calcination temperature is lower than 700 ° C., the crystallinity of the obtained powder is lowered and the capacity of the produced lithium titanium oxide is decreased. When the calcination temperature is higher than 900 ° C., an impurity peak is formed, It is undesirable because particle growth may occur.

The heat treatment process may be performed in an atmosphere selected from the group consisting of a nitrogen gas, an argon gas, an argon / hydrogen mixed gas, and a nitrogen / hydrogen mixed gas.

In the present invention, lithium compounds and titanium compounds used as raw materials for lithium titanium oxide are as follows:

The lithium compound is at least one selected from the group consisting of Li ₂ CO ₃ , LiOH, LiNO ₃ , Li ₂ C ₂ O ₄ , Li ₃ PO ₄ , Li ₂ HPO ₄ , LiHCO ₃ , LiOOCCH ₃ , It may be selected from the group consisting of LiVO ₃ and combinations thereof. The titanium compound may be selected from the group consisting of TiO ₂ , TiH ₂ , TiCl ₄ , TiN, C ₁₂ H ₂₈ O ₄ Ti, and combinations thereof. However, the lithium compound and the titanium compound are not limited to those exemplified above, and any compound can be used without limitation as long as it is a compound commonly used as a source of a lithium element or a titanium element in the production of lithium titanium oxide.

The lithium titanium oxide prepared from the method of controlling the structure and density of the titanium compound as described above and reacting it with the lithium compound slurry can be produced by a conventional method of producing lithium titanium oxide, that is, a method in which a lithium compound and a titanium compound, Mixing together, stirring, pulverizing, and then removing the solvent and drying the lithium titanium oxide; A lithium titanium oxide obtained by mixing a raw material in a powder state; It is possible to manufacture a high-density electrode plate when it is used as an electrode active material as compared with lithium-titanium oxide obtained by recovering a precursor of lithium-titanium oxide from a mixed solution of raw materials by an electrochemical method, have.

Accordingly, the present invention provides an electrode manufactured using the lithium titanium oxide as an electrode active material. The electrode can be prepared by methods well known in the art. That is, a conductive material for imparting electrical conductivity together with lithium titanium oxide and a binder capable of bonding to the current collector are added to and stirred in a dispersant to prepare a paste, which is then applied to a current collector of a metallic material, And dried to produce a laminate-shaped electrode. The conductive material generally contains carbon black in an amount of 1 to 30% by weight based on the total weight of the conductive material. Representative examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF) or a copolymer thereof, and cellulose. Representative examples of the dispersing agent include isopropyl alcohol, N-methylpyrrolidone NMP), acetone, and the like.

The current collector of the metal material may be any metal that has high conductivity and is a metal that can easily adhere the paste of the material and does not have reactivity in the voltage range of the battery. As a representative example, there are a mesh, a foil and the like such as aluminum or stainless steel.

The present invention also provides a lithium secondary battery comprising the electrode of the present invention. The lithium secondary battery can be manufactured using a method known in the art. For example, a separator may be placed between an anode and a cathode, and a non-aqueous electrolyte may be added. As the separation membrane, a porous separation membrane can be used, and a polypropylene-based, polyethylene-based, or polyolefin-based porous separation membrane can be used, but the present invention is not limited thereto.

The nonaqueous electrolytic solution is prepared by mixing a cyclic carbonate such as ethylene carbonate (EC), propylene carbonate (PC), and gamma butyrolactone (GBL) and a solvent such as diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (MPC), and the like. The nonaqueous electrolytic solution may include a lithium salt such as LiClO 4, LiCF ₃ SO ₃ , LiPF ₆ , LiBF ₄ , LiAsF ₆ , and LiN (CF ₃ SO ₂ ) ₂ .

Hereinafter, the present invention will be described in detail with reference to examples. It is to be understood, however, that the following examples are given by way of illustration only for the understanding of the present invention, and therefore the present invention should not be construed as being limited thereby.

Example  One

[Production of titanium compound structure]

100 g of TiO ₂ (reagent grade of Aldrich) having a particle size of 100 nm was placed in 200 g of water and sufficiently stirred with a mechanical agitator. At this time, the rotating speed was set to RPM 1000. Next, the agitated slurry was pulverized at a peripheral speed of 7.5 m / s in a beads-mill using 0.65 mm ZrO ₂ Bead. The pulverized slurry was dried using a nozzle type spray dryer. At this time, the nozzle was subjected to a nozzle pressure condition of 5 kgf / cm ² . The dried powder was heat-treated at 800 ° C for 2 hours in an atmospheric oxidation furnace to obtain a TiO ₂ structure powder.

[Production of lithium titanium oxide]

15.52 g of LiOH (reagent grade of Aldrich) was dissolved in 100 g of water and sufficiently stirred with a mechanical agitator. At this time, the rotating speed was set to RPM 200. Next, 35.67 g of the TiO ₂ structure powder prepared above was added to the solution, and the mixture was sufficiently stirred for 2 hours. At this time, the rotating speed was set to RPM 500. Next, the solution was gradually heated to remove the solvent. Then, the dried powder was heat-treated at 860 ° C for 20 hours in an oxidation furnace in an air atmosphere to obtain a lithium titanium oxide powder.

Example  2

A lithium titanium oxide powder was obtained in the same manner as in Example 1 except that the heat treatment of the lithium titanium oxide in Example 1 was carried out at 860 占 폚 for 10 hours.

Example  3

15.05 g of LiCl (reagent grade of Aldrich) was dissolved in 100 g of ethanol and sufficiently stirred with a mechanical agitator. At this time, the rotating speed was set to RPM 200. Next, 35.10 g of the TiO ₂ structure powder prepared in Example 1 was added to the solution, and the mixture was sufficiently stirred for 2 hours. At this time, the rotating speed was set to RPM 500. Next, the solution was gradually heated to remove the solvent. Then, the dried powder was heat-treated at 860 ° C for 20 hours in an oxidation furnace in an air atmosphere to obtain a lithium titanium oxide powder.

Example  4

A lithium titanium oxide powder was obtained in the same manner as in Example 3, except that the heat treatment of the lithium titanium oxide in Example 3 was carried out at 860 占 폚 for 10 hours.

Comparative Example  One

100 g of TiO ₂ (reagent grade of Aldrich) having a particle size of 100 nm and 36.8 g of LiLi ₂ CO ₃ (reagent grade of Aldrich) were added to 300 g of water and sufficiently stirred with a mechanical agitator. At this time, the rotating speed was set to RPM 1000. Next, the agitated slurry was pulverized at a peripheral speed of 8 m / s in a beads-mill using 0.65 mm ZrO ₂ Bead. The grinding was terminated when the D _max of the particle size analysis was less than 3 μm. The pulverized slurry was dried using a nozzle type spray dryer. At this time, the nozzle pressure was 5 kgf / cm ^{2, and} the nozzle pressure was 5 kgf / cm ² . The dried powder was heat-treated at 850 ° C for 4 hours in an atmospheric oxidation furnace to obtain a lithium titanium oxide powder.

Comparative Example  2

LiCl (reagent grade of Aldrich) and TiOCl ₂ (reagent grade of Aldrich) were each made to a concentration of 2.0 mol / L and mixed. At this time, the mixing ratio of LiCl and TiOCl ₂ solution was such that the molar ratio of [LiCl]: [TiOCl ₂ ] was 4: 5. This mixed solution was put into a reactor, and then sufficiently stirred with a mechanical agitator. At this time, the rotating speed was set to RPM 1440. The temperature of the reactor was maintained at 25 占 폚.

The voltage circulation was applied 100 times at 50 mV / sec between 0.5 and 1.5 V using a connected Electrochemical Analyzer (CHI 604A, CH Instruments Inc.). After the voltage circulation was terminated, the LTO precursor on the platinum mesh surface was recovered. The recovered precursor was washed with pure water to a pH of 5 or higher. The washed precursor was dried using a nozzle-type spray dryer. At this time, a nozzle pressure condition of 5 kgf / cm ² was used. The dried powder was subjected to heat treatment at 850 ° C for 4 hours in an atmospheric oxidation furnace to obtain a lithium titanium oxide powder.

[SEM analysis of lithium titanium oxide]

SEM photographs of the lithium titanium oxide powders prepared in Example 1 and Comparative Example 1 were performed. Photographs taken are shown in Figs. 3 and 4, respectively.

It was confirmed that the powder prepared in Example 1 had less pore and higher density than the powder prepared in Comparative Example 1. [

[Evaluation of characteristics of lithium titanium oxide powder]

Pellets  Density evaluation

The lithium titanium oxide prepared in the above Examples and Comparative Examples was pelletized by compression under the pressure shown in Table 1 below. Thereafter, the density of the pellets was measured.

The pressure at the time of pelletization and the density of the produced pellets are shown in Table 1 below.

Pellet density (g / cm ³ ) Compression pressure 1.0 (ton / cm ² ) 1.5 (ton / cm ² ) 2.0 (ton / cm ² ) Example 1 2.03 2.10 2.17 Example 2 1.96 2.03 2.10 Example 3 2.01 2.07 2.16 Example 4 1.96 2.00 2.08 Comparative Example 1 1.62 1.72 1.79 Comparative Example 2 1.61 1.70 1.79

As shown in Table 1, the pellet density of the comparative powders did not exceed 1.8 g / cm ³ even when the pellets were produced under a compression pressure of ² ton / cm ² . It can also be seen that pellet densities are similar in Comparative Example 1 and Comparative Example 2 regardless of the synthesis method.

The pellet is 1.0ton / if produced in a small contact pressure of the cm ² refers to the nearest pellet density to 2.0 g / cm ^3, manufactured under 1.5ton / cm ² or more produced from the contact pressure, while the embodiment lithium titanium oxide powder cases exhibited high values of the pellets were prepared by having 2.0 g / cm ³ or more high density, in particular a pressure of 2.0ton / cm ² 2.1 to 2.2. On the other hand, this phenomenon became more apparent in Examples 1 and 3 in which the heat treatment time was 20 hours.

From the above results, it can be seen that controlling the structure and density of the titanium compound to be a raw material of lithium titanium oxide in the present invention can be a means for controlling the density of pellets produced from the lithium titanium oxide powder when the lithium titanium oxide powder is pelletized . That is, a high-density electrode material lithium titanium oxide can be produced from a titanium compound structure having a high density.

Evaluation of discharge capacity cell characteristics

Electrodes using the lithium titanium oxide powders prepared in the above Examples and Comparative Examples as negative electrode active materials were prepared, and then the characteristics of the coin type semiconductors containing the lithium titanium oxide powders were evaluated.

The coin type (type 2032) was prepared by mixing 2.02 g of PVdF (poly-vinylenedene fluoride) with 31.69 g of NMP (n-methyl-pyrrolidone) to prepare a sol. Then, the weight ratio of sol: LTO powder: Was 89: 6: 5 to prepare a paste. The paste was placed on an aluminum foil and coated with a doctor blade to a thickness of 120 μm. The coated foil was dried in an oven at < RTI ID = 0.0 > 80 C < / RTI > Thereafter, it was cut into a diameter of 16 mm using a punching machine, and then dried again in a vacuum oven for one day. The separator was fabricated by using PP (polypropylene) with electrolyte wetting. The electrolyte used was an organic electrolyte in which 1 M LiPF ₆ was dissolved in ethylene carbonate (EC: ethylmethyl carbonate): DMC (dimethyl carbonate) = 1: 1: 1.

(High-rate characteristics 5C / 0.2C: the time required for fully charging the battery, 1C is the charging rate for 1 hour, and 5C is the charging time for 1/5 Hour, that is, the rate of charging for 12 minutes). The results are shown in Table 2 below.

Battery characteristics Initial discharge capacity
(mAh / cm ³⁾ High rate characteristic (%)
(5.0C / 0.2C) Example 1 357 98.3 Example 2 339 98.1 Example 3 351 98.4 Example 4 333 98.3 Comparative Example 1 324 98.4 Comparative Example 2 319 97.9

As shown in Table 2, in the case of the lithium titanium oxide powder of the comparative example, the initial discharge capacity was found to be less than 330 mAh / cm ³ .

On the other hand, the embodiment lithium titanium oxide powder is 330 mAh / cm ³ Is produced as an electrode having a high capacity value of the excess, in particular Examples 1 and 3 of the lithium-titanium oxide in excess of 350 mAh / cm ³ An electrode having a high discharge capacity was produced.

In addition, the lithium titanium oxide powders of Examples 1 to 4 exhibited excellent selectivity in terms of the capacity retention rate as the C-rate was increased, while the Comparative Examples 1 and 2 showed a large deviation according to the manufacturing method.

From this, it is confirmed that controlling the particle size of the structure and density of the titanium compound, which is a starting material in the process of producing the lithium titanium oxide powder, can be a means for controlling the capacity of the lithium titanium oxide electrode because it affects the discharge capacity of the electrode. . Such an electrode is also stable in terms of high-rate characteristics and exhibits excellent values.

Claims (9)

Controlling the density and structure of the titanium compound to produce a titanium compound structure from the titanium compound, and reacting the titanium compound structure with a slurry comprising a lithium compound and a solvent,
The step of preparing the structure of the titanium compound
A method for producing lithium titanium oxide (LTO), which comprises pulverizing a titanium compound, spray drying the pulverized titanium compound, and heat treating the dried titanium compound to obtain a titanium compound structure. delete The method of claim 1,
Wherein the heat treatment is performed at a temperature of 700 ° C to 900 ° C for 1 to 4 hours. The method of claim 1,
The titanium compound is _{TiO 2, TiH 2, TiCl 4} , TiN, C 12 H 28 O 4 Ti and a method for manufacturing a lithium titanium oxide (LTO), characterized in that selected from the group comprising a combination thereof. The method of claim 1,
Wherein the lithium compound is selected from the group consisting of Li ₂ CO ₃ , LiOH, LiNO ₃ , Li ₂ C ₂ O ₄ , Li ₃ PO ₄ , Li ₂ HPO ₄ , LiHCO ₃ , LiOOCCH ₃ , LiVO ₃ And combinations thereof. ≪ RTI ID = 0.0 > 11. < / RTI > The method of claim 1,
Wherein the slurry of the lithium compound is an aqueous or non-aqueous slurry. The method of claim 1,
And calcining the reaction product obtained from the reaction of the titanium compound with the lithium compound slurry at a temperature of 700 ° C to 900 ° C for 10 to 20 hours. 8. An electrode for a lithium secondary battery, comprising lithium-titanium oxide produced from any one of claims 1 and 3 to 7. A lithium secondary battery comprising the electrode of claim 8.

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