KR101189033B1 - Method of preparing electrode active material for battery and electrode active material for battery prepared by same - Google Patents

Abstract

The present invention relates to a method for producing an electrode active material, comprising the steps of: a) mixing a hydroxide precursor and a phosphate-based compound for providing a metal other than lithium to the electrode active material; b) coating the hydroxide precursor surface with a metal-phosphate compound by adding a metal supply to the mixture prepared in step a); And c) heat treating the coating prepared in step b) with a lithium (Li) compound. Such a production method of the present invention can increase the production process efficiency of the electrode active material, can suppress the growth of the particles of the electrode active material by the heat treatment process and can have a stable structure of the prepared electrode active material.

Description

FIELD OF THE INVENTION AND METHOD OF PREPARING BY ACTIVE MATERIAL FOR BATTERY AND ELECTRODE ACTIVE MATERIAL FOR BATTERY PREPARED BY SAME

The present invention relates to a method for producing an electrode active material for use in a battery (for example, a lithium secondary battery) and an electrode active material, preferably a cathode active material produced by the method.

In general, a lithium secondary battery is prepared by using a material capable of reversibly inserting and detaching lithium ions as a positive electrode active material and a negative electrode active material, and filling an organic electrolyte solution between a positive electrode and a negative electrode. Electrical energy is generated by the oxidation / reduction reaction upon desorption.

Recently, research on positive electrode active materials used in batteries has been actively conducted as part of improving performance and increasing safety of lithium secondary batteries.

A lithium transition metal composite oxide may be used as a cathode active material of the lithium secondary battery, and examples thereof include lithium cobalt (LiCoO ₂ ), lithium manganate (LiMnO ₂ , LiMn ₂ O ₄ ), and lithium nickelate (LiNiO ₂ , LiNi _{1 -X} Co _X O ₂ (0 <X <1) and other solid solution materials.

By the way, Mn-based cathode active materials such as LiMnO ₂ , LiMn ₂ O ₄ can be produced at low cost and have a low pollution to the environment, but are difficult to synthesize, small in capacity, and have structural problems due to the Jahn-teller effect. LiNiO ₂ has the advantage of having a high discharge capacity, but has a disadvantage of short life, difficult synthesis, and poor thermal safety. In addition, LiCoO ₂ has relatively high electrical conductivity, high voltage, and excellent battery characteristics, but has a disadvantage of high price and low stability under high voltage.

Therefore, in order to solve the above problems, various studies have been made on a method of coating a cathode active material such as coating or doping a metal oxide on a lithium transition metal composite oxide.

However, conventional coating method of the positive electrode active material is a method of coating the finally prepared positive electrode active material (for example, LiCoO ₂ ) with a metal oxide dissolved in a solvent such as water or alcohol, this coating method is applied to the positive electrode active material There is a cumbersome problem in the process, such as having to go through additional drying and heat treatment process to remove the water present.

Therefore, Korean Patent Publication No. 10-2003-0088246 (a method for preparing an active material for a battery and a battery active material prepared therefrom) has been proposed to solve the above problem. This technique is one element selected from the group consisting of a compound containing an element (X) capable of forming a double bond with oxygen and an alkali metal, alkaline earth metal, group 13 element, group 14 element, transition metal and rare earth element To prepare a coating solution by adding a compound containing water to (1), to add a metal salt that does not contain lithium to the prepared coating solution and dried to prepare an active material precursor (2), the prepared active material precursor and By reacting to produce a battery active material (3), thereby providing a method for producing an active material exhibiting thermal stability.

However, the above technique uses a dipping method of preparing a coating solution and then adding a metal salt to coat the coating solution. When the metal salt is coated by the deposition method, the coating solution is partially coated on the surface of the metal salt. It is difficult to control the particle size of the active material to be manufactured. That is, as the active material is prepared by reacting with a lithium salt in a state where the coating is not performed on the surface of the metal salt preliminarily, the particle growth control effect of the active material cannot be enjoyed, and thermal stability is higher than that of the active material using a uniformly coated precursor. Falls.

The present invention is to solve the above problems, the manufacturing process is easy to control the particle size of the electrode active material is prepared, and provides a method for producing an electrode active material having excellent thermal stability and the electrode active material prepared by the manufacturing method. It aims to do it.

The present invention to achieve the above object is a) mixing a phosphate-based compound with a hydroxide precursor for providing a metal other than lithium to the electrode active material; b) coating the hydroxide precursor surface with a metal-phosphate compound by adding a metal supply to the mixture prepared in step a); And c) mixing the coating prepared in step b) with a lithium (Li) compound and then heat-treating the same.

In addition, the present invention provides an electrode active material prepared by the above production method.

In addition, the present invention is a positive electrode comprising an electrode active material prepared by the above-described manufacturing method; A negative electrode including a negative electrode active material; A porous separator provided between the anode and the cathode; And it provides a lithium secondary battery comprising an electrolyte solution in which lithium salt is dissolved.

Since the electrode active material according to the present invention can form a uniform metal-phosphate compound coating layer on the surface of the hydroxide precursor by mixing a hydroxide precursor and a phosphate-based compound and then adding a metal supplier, lithium ( Even after heat treatment at a high temperature after mixing with the Li) compound, it is possible to control the excessive growth of the particles of the electrode active material to be produced, to prepare a thermally stable electrode active material, and to increase the efficiency of the manufacturing process of the electrode active material. .

1 is a photograph of an electrode active material of Example 1 and an electrode active material of Comparative Example 2 measured by a scanning electron microscope (SEM).
Figure 2 is a photograph measuring the surface of the electrode active material prepared in Example 1 and Comparative Example 3.
3 is a graph showing charge and discharge capacity changes of the lithium secondary battery including the electrode active materials prepared in Examples 1 to 4 and Comparative Examples 1 and 2, respectively.

Hereinafter, a method for preparing an electrode active material of the present invention and an electrode active material prepared by the method will be described in detail.

< Of electrode active materials  Manufacturing method and prepared by this method Electrode active material >

1. Mixture Manufacturing

A mixture is prepared by mixing a hydroxide precursor and a phosphate compound to provide a metal other than lithium to the electrode active material. At this time, the hydroxide precursor which can be used is not specifically limited, Specifically, it is preferable that it is a compound represented by following formula (1). The hydroxide precursor may have any form, but is preferably in powder form.

[Formula 1]

M (OH) ₂

(In the formula 1, and _{M = Ni 1 -x- y Mn x} Co y , or Mn, 0 <y <0.7, and the ratio of Mn to Ni (x / (1-xy)) is 0.4 to 1 Im)

Such a hydroxide precursor is to perform a core role in the electrode active material to be produced, to form a structure that can act as an electrode active material by reacting with a lithium (Li) compound (for example, Li ₂ CO ₃ ) to be described later. That is, specifically, in Formula 1, M (metal except lithium) and a lithium (Li) compound react to form a core.

On the other hand, in mixing the hydroxide precursor and the phosphate-based compound, in order to ensure that the phosphate-based compound is uniformly present on the surface of the hydroxide precursor, the hydroxide precursor is preferably prepared by dispersing in a particulate state on a solvent (for example, water). Do.

The phosphate compound mixed with the hydroxide precursor is also not particularly limited, but may be selected from the group consisting of, but not limited to, sodium tripolyphosphate, phosphoric acid, and sodium phosphate (NaPO ₄ ).

Such a phosphate-based compound is preferably in the form of a solution dispersed in a solvent in order to be mixed with the hydroxide precursor smoothly, wherein the solvent that can be used is not particularly limited, but non-limiting examples of alcohols such as methanol, ethanol, isopropanol, hexane, Chloroform, tetrahydrofuran, ether, acetone, water and the like. Here, the phosphate-based compound is present in the ionic state as it is dissolved in the solvent phase, the phosphate in the ionic state is uniformly bonded to the surface of the hydroxide precursor particles.

That is, when the hydroxide precursor dispersed in the solvent phase and the solution of the phosphate compound are mixed, the phosphate in the ionic state is uniformly distributed on the surface of the hydroxide precursor particles due to the potential difference on the surface of the hydroxide precursor in the particulate state, and the phosphate system is formed on the surface of the hydroxide precursor particles. To form a compound ion layer.

On the other hand, the phosphate compound can lower the electrical conductivity as it reacts later with the lithium (Li) compound to prevent the prepared electrode active material from occurring side reactions with the electrolyte of the battery, thereby reducing the generation of gas Can improve the thickness characteristics.

2. Coating  Produce

The metal precursor is added to the mixture prepared above to coat the hydroxide precursor surface with a metal-phosphate compound. At this time, the metal supply to be added is not particularly limited, but may be selected from the group consisting of Zr, Al, Na, Co, Mn, Ni, Cu, V, Ti and combinations thereof.

In addition, the metal supplier used in the present invention may include a compound for adjusting the pH to increase the coating power between the hydroxide precursor and the metal-phosphate-based compound. That is, in case of using a metal feeder containing a compound for adjusting pH, the repulsive force between the hydroxide precursor and the metal-phosphate-based compound is reduced by the principle of equivalence where the sum of the charges of the hydroxide precursor and the metal-phosphate-based compound is zero. Because it can reduce the electrical bond is made strong to increase the coating power. Here, the metal supplier including the compound for adjusting the pH is not particularly limited. In the group consisting of aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), aluminum nitrate (Al (No) ₃ ), magnesium sulfate (MgSO ₄ ), titanium sulfate (Ti (SO ₄ ) ₂ ) and zinc sulfate (ZnSO ₄ ) Can be selected.

The metal derived from the metal supplier is present on the surface of the hydroxide precursor. Thus, when the metal is present on the surface of the hydroxide precursor, the electrode active material manufactured may have a stable structure.

On the other hand, according to the present invention, a uniform metal-phosphate compound coating layer is formed on the surface of the hydroxide precursor by mixing the metal supply to the mixture. In other words, when the metal supply is mixed with the mixture, the metal supplied from the metal supply is also present in the mixture in the form of ions. The metal in the form of such ions combines with the phosphate ions bonded to the hydroxide precursor surface to form a uniform metal. A phosphate compound coating layer is formed.

Here, as the uniform metal-phosphate compound coating layer is formed on the surface of the hydroxide precursor, the particle size of the finally prepared electrode active material may be controlled (specifically, particle growth of the electrode active material may be suppressed).

That is, when the electrode active material is prepared by heat treatment after reacting the precursor material with the lithium compound, the particle size (particle size) of the active material grows during the heat treatment process, so that the heat treatment temperature and time are controlled to prepare the electrode active material of a desired size. Should be. By the way, it is difficult to control the particle size of the electrode active material by adjusting the heat treatment temperature and time, and thus, when the electrode active material having large particles is manufactured, the particle size of the electrode active material has to be shredded.

In addition, the heat treatment temperature may be performed at a low temperature (specifically 850 ° C. or lower) to prevent excessive growth of particles of the electrode active material. In the case of heat treatment at low temperature, the structure of the electrode active material is not completed, and when the electrode active material having such an incomplete structure is used, there is a problem that the characteristics of the battery are deteriorated.

However, in the present invention, the metal-phosphate-based compound uniformly coated on the surface of the hydroxide precursor serves as a capping agent, so that the hydroxide precursor coated with the metal-phosphate-based compound is mixed with a lithium (Li) compound and then heat treated to form a final electrode active material. Even if it is prepared, it is possible to suppress the growth of particles of the electrode active material to be produced.

As such, the present invention can control the particle size of the electrode active material, so that only the particle size of the hydroxide precursor may be adjusted to obtain an electrode active material of a desired size, thereby improving the electrode active material manufacturing process efficiency (that is, being excessively grown. When the electrode active material is manufactured, the process that needs to be crushed can be omitted.)

In addition, since the particle size of the electrode active material can be controlled even when heat treatment at a high temperature, it is possible to produce an electrode active material having a stable property to deterioration without excessive grain growth.

On the other hand, when the metal-phosphate-based compound is coated on the hydroxide precursor is dried to remove the solvent to obtain a coating in the form of a powder, in this case, the drying temperature is preferably 100 ~ 200 ℃, among them is made at 100 ℃ good.

3. Coatings and  lithium( Li ) Compound and heat treatment Electrode active material  Produce

The coating prepared in the coating preparation step and the lithium (Li) compound is mixed. At this time, the lithium (Li) compound to be mixed is not particularly limited, but is preferably one compound selected from the group consisting of LiOH, LiOH-H ₂ O and Li ₂ CO ₃ . In addition, the mixing ratio of the prepared coating: lithium (Li) compound is preferably 1 ~ 1.2mol: 1mol.

After mixing the coating material and the lithium compound, heat treatment is performed to produce an electrode active material. At this time, the heat treatment temperature is preferably 900 to 1050 ° C. so that the crystal structure of the electrode active material can be stably formed, and among them, 920 to 980. It is good that it is ° C.

As described above, the electrode active material prepared by the manufacturing method of the present invention has a structure in which a hydroxide precursor forms a core layer, and the surface of the hydroxide precursor is uniformly coated with a metal-phosphate compound (shell layer), and lithium silver hydroxide It may have a structure that is distributed in each of the precursor and the metal-phosphate compound. That is, core layer of the electrode active material of the present invention can be represented by _{LiCo 1 -x- y NiMn y O 2} (0≤x≤0.6, 0≤y≤0.5, 0≤x + y≤0.9), shell layer LiCo to _{1 -abc Ni a Mn b MPO 4} (0≤a≤0.6, 0≤b≤0.5, 0≤c≤0.1, 0≤a + b + c≤0.9, M is a metal being derived from the metal precursor) Can be represented.

Meanwhile, the electrode active material of the present invention may be used without particular limitation as long as it is a battery field, but preferably used as a cathode active material of a lithium secondary battery.

<Lithium secondary battery>

The present invention provides a lithium secondary battery including a positive electrode, a negative electrode, a porous separator, and an electrolyte including the electrode active material prepared above, a detailed description of which is as follows.

The positive electrode is prepared in the form of the electrode active material bound to the positive electrode current collector according to conventional methods known in the art, and serves to store and release lithium ions. In this case, the electrode active material includes an electrode active material prepared by the above-described manufacturing method, and a detailed description thereof will be omitted since it is the same as described above. Meanwhile, as the anode current collector, a foil made of aluminum, nickel, or a combination thereof may be used.

The negative electrode is prepared in the form of the negative electrode active material bound to the negative electrode current collector according to conventional methods known in the art, and serves to store and release lithium ions in the same manner as the positive electrode. In this case, as the negative electrode active material, a conventional negative electrode active material which can be used for a negative electrode of a conventional secondary battery may be used, and non-limiting examples include lithium metal or lithium alloy, coke, artificial graphite, natural graphite, organic polymer compound combustion body, carbon Fibers and the like. As the cathode current collector, stainless steel, nickel, copper, titanium, or an alloy thereof may be used.

The porous separator is provided between the positive electrode and the negative electrode to prevent a short circuit, and a polymer membrane such as polyolefin, polypropylene, polyethylene, or a multilayer thereof, a microporous film, a woven fabric, and a nonwoven fabric may be used.

The electrolyte is a lithium salt is dissolved, the lithium salt is not particularly limited, but non-limiting examples include LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , LiSbF ₆ , LiN (SO ₂ CF ₃ ) ₂ , LiC ₄ F ₉ SO ₃ , LiAlF ₄ , LiAlCl ₄ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiN (C _x F _{2x + 1} SO ₂ ) (C _y F _{2y +1} SO ₂ ), where x and y are natural water), LiCl and LiI can be used in combination with one or two or more.

In addition, the electrolyte solvent in which the lithium salt is dissolved is not particularly limited, and cyclic carbonate, linear carbonate, lactone, ether, ester, acetonitrile, lactam, ketone and the like can be used.

Here, examples of the cyclic carbonate include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), fluoroethylene carbonate (FEC), and the like. Examples of the linear carbonate include diethyl carbonate (DEC), Dimethyl carbonate (DMC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC), methyl propyl carbonate (MPC), and the like. Examples of the lactone include gamma butyrolactone (GBL), and examples of the ether include dibutyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane and the like. Examples of such esters include methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl pivalate and the like. In addition, the lactam includes N-methyl-2-pyrrolidone (NMP) and the like, and the ketone includes polymethylvinyl ketone. These electrolyte solution solvents can be used individually or in mixture of 2 or more types.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following examples are only preferred embodiments of the present invention and the present invention is not limited to the following examples.

[ Example  One]

1-1. Electrode active material  Produce

300 g of NiCoMn (OH) ₂ was added to 1 L of distilled water, followed by stirring to prepare a hydroxide precursor. STPP solution was prepared by dissolving 300 ppm of STPP in 100 ml of distilled water, and then STPP solution and hydroxide precursor were added to the reactor and stirred for 100 minutes. Thereafter, Al ₂ (SO ₄ ) ₃ solution was added, stirred for about 60 minutes while adjusting the pH, and the resultant was dried at 105 ° C. After drying and mixing the resultant Li ₂ CO ₃ and the heat treatment at 980 ℃ to prepare an electrode active material, at this time, the size of the prepared electrode active material particles were measured and the results are shown in Table 1 below. On the other hand, the coating amount (concentration) of the metal-phosphate compound coated on the precursor was 300 ppm.

1-2. Lithium secondary battery manufacturing

The electrode active material prepared above was mixed with a cathode active material, carbon black as a conductive material, and PVDF with a binder in a weight ratio of 95: 2.5: 2.5, and these were added to NMP as a solvent to prepare a positive electrode slurry, followed by an aluminum current collector. A positive electrode was prepared by coating on (Al), and Li-metal was used as the negative electrode.

A lithium secondary battery was fabricated by interposing a polyolefin-based separator between the positive electrode and the Li-metal negative electrode (manufacturer: FMC) prepared as described above, and injecting EC: EMC: DMC (1: 1: 1) into the electrolyte. It was.

[ Example  2 to 4 and Comparative example  1 to 2]

An electrode active material and a lithium secondary battery were manufactured in the same manner as in Example 1, except that the components, heat treatment temperatures, and coating amounts of Table 1 were applied.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 hydroxide
Precursor
(Particle size) NiCoMn (OH) ₂
(11 μm) NiCoMn (OH) ₂
(11 μm) NiCoMn (OH) ₂
(11 μm) NiCoMn (OH) ₂
(11 μm) NiCoMn (OH) ₂
(11 μm) NiCoMn (OH) ₂
(11 μm) Lithium compounds
(Particle size) Li ₂ CO ₃
(7 μm) Li ₂ CO ₃
(7 μm) Li ₂ CO ₃
(7 μm) Li ₂ CO ₃
(7 μm) Li ₂ CO ₃
(7 μm) Li ₂ CO ₃
(7 μm) Force
Fate system
compound STPP STPP STPP STPP - STPP Metal supply Al ₂ (SO ₄ ) ₃ Al ₂ (SO ₄ ) ₃ Al ₂ (SO ₄ ) ₃ Al ₂ (SO ₄ ) ₃ - Al ₂ (SO ₄ ) ₃ Metal-Phosphate
Compound coating amount
(ppm) 300 300 300 300 - 300 Heat treatment temperature
(℃) 980 960 940 920 920 850 Final electrode active material particle size
(Unit: 占 퐉) 11.06 11.04 11.07 11.03 13.3 12.4

Looking at Table 1, it can be seen that Examples 1 to 4 according to the present invention can control the particle size of the prepared electrode active material because there is almost no particle difference between the hydroxide precursor and the prepared electrode active material. However, Comparative Examples 1 and 2 was confirmed that the difference in the particle size between the used hydroxide precursor and the prepared electrode active material is not coated with a metal-phosphate-based compound or low firing temperature.

In addition, as a result of analyzing the electrode active materials prepared in Example 1 and Comparative Example 2 by a scanning electron microscope (SEM), Example 1 fired (980 ° C) within the heat treatment temperature range of the present invention, the particles were uniform. While the prepared electrode active material had a spherical stable shape, it could be confirmed that Comparative Example 2 fired at a low temperature (850 ° C.) showed that the electrode active material had a non-uniform particle shape but showed an unstable structure. Could be (see FIG. 1).

[ Comparative example  3]

1-1. Electrode active material  Produce

STPP solution was prepared by dissolving 300 ppm of STPP in 100 ml of distilled water. Then, Al ₂ (SO ₄ ) ₃ solution was added to the reactor and stirred for about 60 minutes to prepare an AlPO ₄ coating solution. After adding 300 g of NiCoMn (OH) ₂ to 1 L of distilled water, the AlPO ₄ coating solution was added twice, stirred for 100 minutes, and then the resultant was filtered and dried at 105 ° C. After drying and mixing the resultant Li ₂ CO ₃ and the heat treatment at 980 ℃ to prepare an electrode active material, the size of the prepared electrode active material particles was measured and the results are shown in Table 2 below.

Comparative Example 3 Hydroxide precursor
(Particle size) NiCoMn (OH) ₂
(11 μm) Lithium compounds
(Particle size) Li ₂ CO ₃
(7 μm) Phosphate compounds STPP Metal supply Al ₂ (SO ₄ ) ₃ Coating amount of metal-phosphate compound (ppm) 300 Heat treatment temperature (캜) 980 Final electrode active material particle size
(Unit: 占 퐉) 13.4

Referring to Table 2, when the coating solution including the phosphate-based compound is first prepared, and then coated on the hydroxide precursor to prepare the electrode active material, the size of the prepared electrode active material particles is larger than that of the used hydroxide precursor particles, thereby controlling the particle size of the electrode active material. Could not be confirmed.

2 is an image of the electrode active materials prepared in Example 1 and Comparative Example 3 analyzed by Transmission Electron Microscopy (TEM), and the electrode active materials prepared in Example 1 exhibit a uniform surface. It was confirmed that the electrode active material prepared in Comparative Example 3 exhibits an uneven surface.

[ Test Example  1] Performance Evaluation of Lithium Secondary Battery

After charging and discharging the lithium secondary batteries prepared according to Examples 1 to 4 and Comparative Examples 1 to 2 at 0.1 C, 0.2 C, 0.5 C, 1 C, and 2 C in a charge and discharge voltage range of 3.0 to 4.3 V, Charge and discharge capacity according to the C-rate was measured, the measurement results are shown in Table 3 and FIG.

(Chg: charge capacity, Dis-Chg: discharge capacity, charge and discharge efficiency (%) = discharge capacity / charge capacity × 100)

Looking at the Table 3 and Figure 3 it was confirmed that the charge and discharge efficiency of the lithium secondary battery including the electrode active material of the present invention is higher than the comparative examples.

Claims (10)

a) mixing a hydroxide precursor and a phosphate-based compound to provide a metal other than lithium to the electrode active material;
b) coating the hydroxide precursor surface with a metal-phosphate compound by adding a metal supply to the mixture prepared in step a); And
c) mixing the coating prepared in step b) with a lithium (Li) compound, followed by heat treatment. The method of claim 1,
The hydroxide precursor is a method for producing an electrode active material, characterized in that the compound represented by the formula (1).
[Formula 1]
M (OH) ₂
(In the formula 1, and _{M = Ni 1 -x- y Mn x} Co y , or Mn, 0 <y <0.7, and the ratio of Mn to Ni (x / (1-xy)) is 0.4 to 1 Im) The method of claim 1,
The phosphate compound is a method for producing an electrode active material, characterized in that selected from the group consisting of sodium tripolyphosphate (Sodium Tripolyphosphate), phosphoric acid (Phosphoric acid) and sodium phosphate (NaPO ₄ ). The method of claim 1,
The metal supplier is Zr, Al, Na, Co, Mn, Ni, Cu, V, Ti and a method for producing an electrode active material, characterized in that selected from the group consisting of a combination thereof. The method of claim 1,
The metal supply method of producing an electrode active material, characterized in that it comprises a compound for adjusting the pH to increase the coating power between the hydroxide precursor and the metal-phosphate-based compound. The method of claim 5,
The metal supplier including the compound for adjusting the pH is aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), aluminum nitrate (Al (No) ₃ ), magnesium sulfate (MgSO ₄ ), titanium sulfate (Ti (SO ₄ ) ₂ ) and zinc sulfate (ZnSO ₄ ) method for producing an electrode active material, characterized in that selected from the group consisting of. The method of claim 1,
The lithium (Li) compound is a method for producing an electrode active material, characterized in that selected from the group consisting of LiOH, LiOH H ₂ O and Li ₂ CO ₃ . The method of claim 1,
Heat treatment temperature in the step c) is a method for producing an electrode active material, characterized in that 900 ~ 1050 ℃. An electrode active material prepared by the method of any one of claims 1 to 8. A positive electrode comprising an electrode active material prepared by the method of any one of claims 1 to 8;
A negative electrode including a negative electrode active material;
A porous separator provided between the anode and the cathode; And
A lithium secondary battery comprising an electrolyte solution in which lithium salt is dissolved.

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