KR20040058667A - The cathode active material for lithium secondary batteries and the preparation method thereof - Google Patents

Abstract

PURPOSE: A cathode active material for lithium secondary battery is provided to improve the cycle life, capacity and service life at high temperature of a battery, due to its electrochemical stability in a wide range of voltage. CONSTITUTION: The cathode active material for a lithium secondary battery having 0.1-20 micrometer of particle size, comprises: a compound selected from Lix£Li(y/3)A(2y/3)Co(1-y)|O2zBO2 and Lix£Li(y/3)A(2y/3)Co(1-y)|O2zLi2BO3, in which A is selected from Ti, Mn and Ni; B is selected from Zr, Mo, Ru and Sn; and x, y and z satisfy the following inequalities: 0.9<x<1.1, 0<y<0.5 and 0<z<0.5. The positive electrode active material is prepared by a liquid phase method comprising the steps of: (i) preparing a mixed solution of: a water soluble compound containing cobalt; a water soluble compound containing lithium; and a water soluble compound containing at least one selected from Ti, Mn and Ni; (ii) adding a chelating agent to the solution from the step (i) to give a gel; and (iii) heating and milling the gel obtained from the step (ii).

Description

Cathode active material for lithium secondary battery and manufacturing method thereof {THE CATHODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERIES AND THE PREPARATION METHOD THEREOF}

The present invention relates to a novel lithium secondary battery positive electrode active material and a method of manufacturing the same.

Recently, as miniaturization and light weight of electronic equipment have been realized, and the use of portable electronic devices has become common, research on lithium secondary batteries having high energy density as a power source of portable electronic devices has been actively conducted.

The lithium secondary battery is manufactured by using a material capable of intercalation and deintercalation of lithium ions as a negative electrode and a positive electrode, and filling an organic electrolyte or polymer electrolyte capable of moving lithium ions between the positive electrode and the negative electrode, Lithium ions generate electrical energy by oxidation and reduction reactions during insertion / desorption of lithium ions at the positive and negative electrodes.

With a positive electrode (cathode) active material of the lithium secondary battery is kalko halogenated (chalcogenide) compounds of the insertion and desorption is a metal of the lithium ions are used, but since the 1970s, can be seen the energy density and because of the low operating voltage, LiCoO _2, Composite metal oxides such as LiMn ₂ O ₄ , LiNiO ₂ , LiNi _1-y Co _y O ₂ (0 <y <1), LiMnO _2, and the like have been replaced and utilized or studied. Among the positive electrode active materials, LiNiO ₂ has a large charging capacity but is difficult to synthesize. Mn-based active materials such as LiMn ₂ O ₄ and LiMnO ₂ are easy to synthesize, relatively inexpensive, and have excellent stability compared to other materials. And, there is a small environmental pollution, but there is a disadvantage that the capacity is small. In addition, LiCoO ₂ is widely used at room temperature because it exhibits electrical conductivity of about 10 ^-3 to 10 ^-1 S / cm, high battery operating voltage, and excellent electrode characteristics. It has the most expensive problem. However, except for lithium secondary batteries of some companies, most of the materials are using LiCoO ₂ as an anode material.

However, LiCoO ₂ cathode material exhibits excellent reversibility in a limited region (x <0.5, Li _1-x CoO ₂ ), but when the lithium ions of x> 0.5 or more are detached, there is a problem that battery performance is rapidly deteriorated. Therefore, various methods have been proposed to solve this problem, but methods of substituting Co ions with other metal ions have been studied, but have not achieved a significant performance improvement. Recently, however, methods have been developed for coating LiCoO ₂ powders with other metal oxides, which have been found to be very effective. For example, Korean Patent No. 1002777960000 discloses a method for producing LiCoO ₂ metal oxides on which a metal oxide is surface-treated by coating a metal alkoxide sol on LiCoO ₂ substituted with other metal ions, followed by heat treatment. have.

The active material is prepared by the method because it requires a separate process and then to a metal oxide coating on LiCoO ₂ (after heat treatment the sol coating), causing a cost increase of the LiCoO ₂ material.

The present invention is to analyze the problems of the prior art, to synthesize particles having a core-shell (core-shell) form through a single heat treatment without a post-treatment process, the core LiCoO ₂ -Li ₂ is a new solid solution system A new method for synthesizing the anode composition of AO ₃ (A = Ti, Mn, Ni) and coating the metal compound having a composition of BO ₂ to Li ₂ BO ₃ (B = Zr, Mo, Ru, Sn) on the shell To synthesize a lithium cobalt-based metal oxide, and to use it as a cathode active material of a lithium secondary battery.

1 is a graph showing the change in lattice constant according to the amount of metal ions added to each material synthesized in a similar manner to Example 1 of the present invention.

Figure 2 is a simplified schematic diagram of the preparation method of Example 1 of the present invention.

3 is a scanning electron micrograph of a LiCoO ₂ powder substituted with Mn and coated with SnO ₂ synthesized by Example 1 of the present invention.

4 is a scanning electron micrograph of the LiCoO ₂ powder synthesized in Comparative Example 1 of the present invention.

5 is a scanning electron micrograph of LiCoO ₂ powder substituted with only Mn synthesized by Comparative Example 2 of the present invention.

FIG. 6 is a scanning electron micrograph of LiCoO ₂ powder substituted with Mn synthesized by Example 2 of the present invention and coated with Li ₂ SnO ₃ .

7 is a graph showing charge and discharge life characteristics of a battery according to Example 3 of the present invention.

8 is a graph showing charge and discharge life characteristics of a battery according to Example 4 of the present invention.

9 is a graph showing the high temperature charge and discharge life characteristics of the battery according to Example 5 of the present invention.

The present invention provides a novel compound represented by the following Formula 1 or 2, the compound may be used as a positive electrode active material for a lithium secondary battery.

[Formula 1]

Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ zBO ₂

[Formula 2]

Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ zLi ₂ BO ₃

(A in Formula 1 to 2, A is selected from the group consisting of Ti, Mn, and Ni, B is selected from the group consisting of Zr, Mo, Ru and Sn, 0.9 <x <1.1, 0 <y <0.5 0 <z <0.5).

It is preferable that the positive electrode active material for lithium secondary batteries is 0.1-20 micrometers in particle size.

Figure 1 shows the lattice constant of the c-axis of LiCoO ₂ in order to more easily understand the results of X-ray diffraction analysis of LiCoO ₂ powder made by changing the type and amount of metal ions substituted by the method of Example 1 below . In FIG. 1, the change in lattice constant with increasing Mn substitution means that LiCoO ₂ and Li ₂ MnO ₃ form a solid solution, whereas the change in lattice constant with increasing Sn substitution does not change the surface of LiCoO _2. Li ₂ SnO ₃ is coated on means that the present in the form of a composite (composite). In addition, when Mn is substituted and Sn is coated, the lattice constant value is similar to that when Mn is substituted, which means that Mn is substituted but Sn is not substituted and the surface is coated.

At this time, whether a solid solution or a coating composite is formed is related to the radius of the substituted metal ion and the radius of Co ion. That is, Ti ions, Mn ions, or Ni ions whose radius of the substituted metal ions are similar to Co ions are easily replaced by Co sites, so that solid solutions are formed, and Zr ions, Mo ions, Ru ions, or Sn ions have a radius of Co ions. It is too large for, so it does not enter the structure and forms a complex.

Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ .zBO ₂ of Formula 1 is a complex of Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ and zBO _2. In particular, the present invention indicates that zBO ₂ is coated on the particle surface of Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ .

Similarly, Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ zLi ₂ BO ₃ of Formula ₂ is Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ and zLi ₂ It indicates that it is a composite of BO ₃ , and in particular, in the present invention, zLi ₂ BO ₃ is coated on the particle surface of Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ .

Which of the complexes of the complex of Formula 1 and complex of Formula 2 is formed is determined by the equivalent ratio of Li, Co, B administered during preparation of the complex.

In Formulas 1 and 2, Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ means a solid solution of LiCoO ₂ -Li ₂ AO ₃ (A = Ti, Mn, Ni).

The compounds of Formulas 1 and 2 may be prepared by the novel liquid phase reaction method or the solid phase reaction method as follows.

First, the manufacturing method by the liquid phase reaction method is as follows.

Water-soluble compounds containing cobalt (eg, cobalt hydroxide, cobalt nitrate, or cobalt acetate, cobalt oxalate, cobalt sulfate, cobalt chloride, etc.); Water-soluble compounds containing lithium (eg, lithium nitrate, lithium acetate, lithium hydroxide, lithium sulfate, etc.); And water-soluble compounds (e.g., hydroxides, nitrates, acetates, chlorides, etc. of each metal) containing at least one of titanium, manganese, nickel as a substitution metal and one or more of zirconium, molybdenum, ruthenium and tin as the coating metal. Mix in the desired equivalence ratio.

At this time, as a mixing method, for example, a cobalt water-soluble compound, a lithium water-soluble compound, a water-soluble compound of a metal to be substituted, and a water-soluble compound of a metal to be coated are dissolved in distilled water, and the chelating agent is mixed in the same molar ratio as the total amount of metal ions. After dissolving, water is removed from a rotary evaporator (50 ° C.) to form a sol, followed by drying in a vacuum dryer (70 ° C.) for 12 hours to form a gel.

The chelating agent added in the above process captures the metal ions dissolved in the solution, thereby preventing ubiquitous metal ions during sol and gel formation to facilitate mixing. Organic acids are generally used as chelating agents, such as citric acid, acrylic acid, tartaric acid, glycoic acid, and the like.

The gelled amorphous precursor thus prepared was pulverized well, and subjected to primary heat treatment at a temperature of 250 to 350 ° C. for 0.5 to 2 hours, and then subjected to secondary heat treatment at a temperature of 750 to 950 ° C. for 4 to 24 hours to form a chemical formula 1 to 2 in a crystalline state. To prepare a powder of the compound selected from the group consisting of If the primary heat treatment temperature is lower than 250 ℃ when the compound is prepared, there is a problem that the gel polymers do not burn. If the secondary heat treatment temperature is lower than 750 ° C., it is difficult for the crystalline material to be sufficiently produced. The heat treatment step is carried out by increasing the temperature and temperature at a rate of 0.5 ~ 10 ℃ / min under dry air or oxygen, and is maintained for each predetermined time under the heat treatment conditions.

Subsequently, the powders of the compounds of Formulas 1 and 2 prepared are ground by mortar grinding at room temperature.

Next, the manufacturing method by the solid-phase reaction method is as follows.

In order to synthesize the compounds of Formulas 1 and 2, cobalt water-soluble or water-insoluble compounds (eg, cobalt hydroxide, cobalt nitrate, cobalt oxide, cobalt carbonate, cobalt acetate, cobalt oxalate, cobalt sulfate and cobalt chloride, etc.) ); Lithium water-soluble or water-insoluble compounds (eg, lithium nitrate, lithium acetate, lithium hydroxide, lithium carbonate, lithium oxide, lithium sulfate, lithium chloride, etc.); And metals coated with one of titanium, manganese, nickel water-soluble or non-water soluble compounds (e.g., hydroxide side, nitrate, acetate, chloride, carbonate, oxide and sulfate, etc.) of each metal as zirconium, molybdenum, One or more of the water-soluble or water-insoluble compounds of ruthenium and tin (eg, hydroxide side, nitrate, acetate, chloride, carbonate, oxide and sulfate, etc. of each metal) are mixed in the desired equivalent ratio.

The mixing method is, for example, by performing a mortar grinder mixing, the water-soluble or water-insoluble water of the metal coated with the water-soluble or water-insoluble compound of the metal substituted with the cobalt water-soluble or water-insoluble compound, the lithium water-soluble or water-insoluble compound. Mixtures are prepared according to equivalence ratios. In this case, two types of dry and wet mixing methods are possible. The dry method is mixing without a solvent, and the wet method adds an appropriate solvent such as ethanol, methanol, water, acetone, and the like to promote the reaction of the cobalt compound, the lithium compound and the metal compound. The solvent is mixed until it is almost solvent-free, although both are possible but wet method is preferred. Prior to the heat treatment of the mixture thus prepared, it is preferable to compress the pellets, but this process may be omitted.

The mixture prepared through the above process is first heat-treated at 350 to 550 ° C. for 1 to 10 hours, and second to heat treatment at 750 to 950 ° C. for 4 to 24 hours to prepare compound powders of Chemical Formulas 1 and 2 in a crystalline state. . When the primary heat treatment temperature is lower than 350 ° C. when preparing the compound powder in the crystalline state, there is a problem in that the reaction between the cobalt compound and the lithium compound is not sufficient. If the secondary heat treatment temperature is lower than 750 ° C., it is difficult to form a crystalline material. The heat treatment step is performed by increasing the temperature and decreasing the temperature at a rate of 0.5 to 10 ° C / min under dry air or oxygen, and maintaining the fixed time at each heat treatment temperature.

Subsequently, the prepared compound powders of Formulas 1 and 2 are ground by mortar grinding.

Electrodes of the battery are prepared using the compounds of Formulas 1 and 2 prepared above. In addition to the active material, the preparation of the electrode requires a conductive material for providing electrical conductivity and a binder that enables adhesion between the material and the current collector. The paste was prepared by adding and stirring a conductive material in a weight ratio of 1 to 30 wt% and a binder in a weight ratio of 1 to 10% with respect to the positive electrode active material prepared by the above method, and then adding the mixture to a dispersant and collecting the metal material. It is applied to the whole, compressed and dried to prepare a laminate electrode.

The conductive material generally adds carbon black at 1 to 30% by weight based on the total weight. Products currently marketed as conductive materials include acetylene black series (Chevron Chemical Company or Gulf Oil Company), Ketjen Black EC series (Armak Company (Armak) Company), Vulcan XC-72 (manufactured by Cabot Company) and Super P (MMM).

Representative examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), or a copolymer thereof, cellulose, and the like, and representative examples of the dispersant are isopropyl alcohol and N-methylpyrroli. Money (NMP) and acetone.

The current collector of the metal material is a metal having high conductivity, and any metal can be used as long as the paste of the material is easily adhered and is not reactive in the voltage range of the battery. Representative examples include meshes, foils, and the like, such as aluminum or stainless steel.

The method of apply | coating the paste of an electrode material to a metal material can be selected from a well-known method in consideration of the characteristic of a material, or can be performed by a new suitable method. This example is to distribute the paste onto the current collector, and then to uniformly disperse it using a doctor blade or the like. In some cases, a method of distributing and dispersing in one process may be used. In addition, diecasting, comma coating, and screen printing can be selected. Alternatively, after molding on a separate substrate, it can be in contact with the current collector by pressing or lamination method.

An example of a method of drying the applied paste is dried for 1 to 3 days in a vacuum oven at 50 to 200 ℃.

In the method of constructing a lithium secondary battery using the electrode manufactured by the above method, for example, the electrode is used as an anode, a metal lithium or an alloy-based material is used as a cathode, and a separator is inserted therebetween. The membrane blocks the internal short circuit of the two electrodes and impregnates the electrolyte, and materials that can be used include polymer, glass fiber mat, kraft paper, etc.Cellgard 2400, 2300 ( Hoechest Celanese Corp.), polypropylene membrane (manufactured by Ube Industries Ltd. or Pall RAI).

The electrolyte is a system in which a lithium salt is dissolved in an organic solvent, and the lithium salt is LiClO ₄ , LiCF ₃ SO ₃ , LiAsF ₆ , LiBF ₄ , LiN (CF ₃ SO ₂ ) ₂ , LiPF ₆ , LiSCN, and LiC (CF ₃ SO _{2 3,} etc., and the organic solvent is ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC), 1,2-dime 1,2-dimethoxyethane, 1,2-diethoxyethane, gamma-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran 2-methyltetrahydrofuran), 1,3-dioxolane (1,3-dioxolane), 4-methyl-1,3-dioxolane (4-methyl-1,3-dioxolane), diethylether, Sulfolane etc. can be used 1 type or in mixture of 2 or more types.

The present invention will be described in more detail with reference to the following examples. However, an Example is for illustrating this invention and is not limited only to these.

EXAMPLE

Example 1

Mn Substituted SnO ₂ Coated LiCoO ₂ Synthesis by Liquid Phase Reaction of Chemical Formula 1

LiNO ₃ 1.033 _{mol, Co (NO 3) 2 ·} 6H 2 O 0.9 _{mol, Mn (NO 3) 2 ·} 6H 2 O 0.067 mole and ₂ · 2H ₂ O was dissolved SnCl 0.03 moles in distilled water. 2.03 mol of citric acid was added thereto, mixed, and completely dissolved. Then, water was removed from a rotary evaporator (50 ° C.) to make a sol, and dried in a vacuum dryer (70 ° C.) for 12 hours to make a gel. This was subjected to a first heat treatment at 300 ° C. for 30 minutes and further heat treated at 900 ° C. for 10 hours. At this time, the temperature rising and temperature decreasing rate were 1 degree-C / min. The powder thus prepared was ground in mortar at room temperature to prepare a cathode active material of a lithium secondary battery. Crystalline (Li [Li _{0.1 / 3} Mn _{0.2 / 3} Co _0.9 ] O ₂ · 0.03SnO ₂ ) powder prepared by the above method has a plurality of primary particles having a particle size of 0.2 μm and a particle size of 2 to 3 μm. Phosphorus secondary particles are formed. Figure 3 shows the shape of the other particles coated on the surface of Li [Li _{0.1 / 3} Mn _{0.2 / 3} Co _0.9 ] O ₂ .0.0SnO _{2 prepared} in the above embodiment, which was analyzed by Auger spectroscopy result, it was confirmed that SnO _2. Therefore, through one heat treatment as in the first embodiment, it is possible to manufacture a powder coated with Mn on the inner core and SnO ₂ particles on the shell in the form of a core-shell.

Comparative Example 1

1 mol of LiNO _{3 and} 1 mol of Co (NO ₃ ) ₂ .6H ₂ O were dissolved in distilled water. 2 mol of citric acid was added here, mixed, and it melt | dissolved completely. Since the powder manufacturing method was the same as in Example 1. 4 shows a scanning electron micrograph of the powder prepared by the above method, wherein a plurality of primary particles having a particle size of 1 μm are gathered to form secondary particles having a particle size of 4 to 6 μm, and the surface is smooth. It shows shape.

Comparative Example 2

LiNO ₃ 1.033 _{mol, Co (NO 3) 2 ·} 6H 2 O 0.9 mole and _{Mn (NO 3) 2 · 6H} 2 O was dissolved 0.067 mol of distilled water. 2 mol of citric acid was added here, mixed, and it melt | dissolved completely. Since the powder manufacturing method was the same as in Example 1. FIG. 5 shows a scanning electron micrograph of the crystalline Li [Li _{0.1 / 3} Mn _{0.2 / 3} Co _0.9 ] O ₂ powder prepared by the above method, wherein a plurality of primary particles having a particle size of 0.5 μm are collected and have a particle size. It is a state in which the secondary particle which is 2-3 micrometers was formed, and the surface has a smooth shape.

Example 2

Mn Substituted Li ₂ SnO ₃ Coated LiCoO ₂ Synthesis by Liquid Phase Reaction of Chemical Formula 2

LiNO ₃ 1.1 _{mol, Co (NO 3) 2 ·} 6H 2 O 0.9 _{mol, Mn (NO 3) 2 ·} 6H 2 O 0.067 mole and ₂ · 2H ₂ O was dissolved SnCl 0.03 moles in distilled water. 2.07 moles of citric acid was added thereto, mixed, and completely dissolved. Since the powder manufacturing method was the same as in Example 1. The crystalline (Li [Li _{0.1 / 3} Mn _{0.2 / 3} Co _0.9 ] O ₂ · 0.03Li ₂ SnO ₃ ) powder prepared by the above method has a plurality of primary particles having a particle size of 0.5 μm, and has a particle size of 2˜. It is the state which formed the secondary particle which is 3 micrometers. FIG. 6 shows Li ₂ SnO ₃ coated powder made of Example 2, and shows other particles coated on the surface, which was confirmed to be Li ₂ SnO ₃ by Auger spectroscopy.

Example 3

Mn-substituted SnO ₂ coated LiCoO ₂ prepared in Example 1 was used as an active material, and the conductive material was Ketjen Black EC, and the polytetrafluoroethylene (PTFE) was used as a binder in a weight ratio of 7: 2: 1 to prepare a paste by attaching to a stainless steel mesh current collector to prepare a working electrode, which was dried for 10 hours or more in a 120 ℃ vacuum oven. Using a lithium metal foil as the counter electrode and the reference electrode in a dry box in an argon atmosphere, and using a 1 molar concentration LiPF ₆ / EC: DMC (volume ratio 1: 2) as an electrolyte, a beaker type 3-pole cell was used. And constant current / constant voltage experiments were performed at 25 ° C.

7 shows Li [Li _{0.1 / 3} Mn _{0.2 / 3} Co _0.9 ] O ₂ · 0.03SnO ₂ synthesized in Example 1, LiCoO ₂ prepared in Comparative Example 1, and Mn prepared in Comparative Example 2 substituted with Li [ The capacity per weight according to charge / discharge of Li _{0.1 / 3} Mn _{0.2 / 3} Co _0.9 ] O ₂ at room temperature of the electrode using the positive electrode active material is illustrated.

As can be seen in Figure 7, the compound of Example 1 in the 3.0 ~ 4.5V (vs. Li / Li ⁺ ) region to confirm the effect that the dose reduction is inhibited compared to the compound of Comparative Example 1 and Comparative Example 2 Can be.

Example 4

Except for the Mn prepared in Example 2 and LiCoO ₂ coated with Li ₂ SnO ₃ as an active material, other conditions were the same as in Example 3. 8 shows only Li [Li _{0.1 / 3} Mn _{0.2 / 3} Co _0.9 ] O ₂ .0.0Li ₂ SnO ₃ synthesized in Example ₂ and LiCoO ₂ prepared in Comparative Example 1 and Mn prepared in Comparative Example 2 substituted with The capacity per weight according to charge / discharge of Li [Li _{0.1 / 3} Mn _{0.2 / 3} Co _0.9 ] O ₂ at room temperature of an electrode using a positive electrode active material is shown.

As can be seen in Figure 8, in the 3.0 ~ 4.5V (vs. Li / Li ⁺ ) region of the compound of Example 2 compared to the compound of Comparative Example 1 and the compound of Comparative Example 2 to confirm the effect that the dose reduction is suppressed Can be.

Example 5

Except that was carried out at 55 ℃ was carried out in the same manner as in Example 3. The results of the battery life characteristics at 55 ° C. are shown in FIG. 9.

The present invention synthesized the core-shell (powder-shell) form of the powder by a liquid phase reaction and a solid state reaction method through one heat treatment. The inner core has a Li [Li _{y / 3 in the} form of LiCoO ₂ -Li ₂ AO ₃ which is a solid solution different from LiCo _1-y M _y O _2, which is a solid solution of LiCoO ₂ -LiMO ₂ (M = metal), which has been disclosed in the existing patent. A _{2y / 3} Co _1-y ] O ₂ (A = Ti, Mn, Ni) is formed to improve the structural stability and the outer shell BO ₂ or Li ₂ BO ₃ (B = Zr, Mo, Ru, Sn) Suppresses the reactivity of the positive electrode active material and the electrolyte. The present invention has the advantage of lowering the cost because the heat treatment process is less than the post-treatment of LiCoO ₂ coating. In addition, it is electrochemically stable in a wide range of voltage range to improve the cycle life of the battery and to provide a high capacity battery, especially exhibits improved high temperature life characteristics.

Claims (11)

A compound represented by the following formula (1) or (2). [Formula 1] Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ zBO ₂ [Formula 2] Li _x [Li _{y / 3} A _{2y / 3} Co _1-y ] O ₂ zLi ₂ BO ₃ (A in Formula 1 to 2, A is selected from the group consisting of Ti, Mn, and Ni, B is selected from the group consisting of Zr, Mo, Ru and Sn, 0.9 <x <1.1, 0 <y <0.5 0 <z <0.5). The compound according to claim 1, wherein the particle size is 0.1 to 20 mu m. i) water-soluble compounds containing cobalt; Water-soluble compounds containing lithium; Water-soluble compounds containing one of titanium, manganese and nickel as a substituted metal; And a first step of preparing a mixed solution of a water-soluble compound containing at least one of zirconium, molybdenum, ruthenium, and tin as a coating metal. ii) a second step of mixing the chelating agent in the mixed solution prepared in the first step to form a gel; iii) A method for preparing the compound of claim 1 by a liquid phase reaction comprising a third step of thermally grinding the gel prepared in the second step. i) water-soluble or water-insoluble compounds containing cobalt; Water-soluble or water-insoluble compounds containing lithium; Water-soluble or water-insoluble compounds containing one of titanium, manganese and nickel as the substituted metal; And a first step of mixing a water-soluble or water-insoluble compound containing at least one of zirconium, molybdenum, ruthenium, tin as the coating metal, ii) A method for preparing the compound of claim 1 by a solid-phase reaction method comprising a second step of thermally grinding the mixture prepared in the first step. The method of claim 3, wherein the gelled amorphous precursor resulting from the second step is subjected to a first heat treatment at 250 to 350 ° C., and a second heat treatment at a temperature of 750 to 950 ° C. 5. The method of claim 3, wherein the chelating agent is selected from one or more of citric acid, acrylic acid, tartaric acid, and glyco acid. The cobalt-containing water-soluble compound according to claim 3, wherein the water-soluble compound containing cobalt is at least one selected from the group consisting of cobalt hydroxide, cobalt nitrate, cobalt acetate, cobalt oxalate, cobalt sulfate, cobalt chloride; The water-soluble compound containing lithium is one or more selected from the group consisting of lithium hydroxide, lithium nitrate, lithium acetate, and lithium sulfate; Water-soluble compound of titanium, manganese, nickel, zirconium, molybdenum, ruthenium, tin as the substituted or coated metal is at least one selected from the group consisting of hydroxide, nitrate, acetate, chloride of each metal. The method of claim 4, wherein in the second step, the mixed precursor resulting from the first step is subjected to a first heat treatment at a temperature of 350 to 550 ° C., and a second heat treatment at a temperature of 750 to 950 ° C. 6. The cobalt-containing water-soluble or water-insoluble compound according to claim 4, wherein the water-soluble or non-aqueous compound containing cobalt is at least one selected from the group consisting of cobalt hydroxide, cobalt nitrate, cobalt oxide, cobalt carbonate, cobalt acetate, cobalt oxalate, cobalt sulfate and cobalt chloride. Selected; The water-soluble or water-insoluble compound containing lithium is one or more selected from the group consisting of lithium nitrate, lithium acetate, lithium hydroxide and lithium carbonate, lithium oxide, lithium sulfate, lithium chloride; Water-soluble or non-aqueous compounds of titanium, manganese, nickel, zirconium, molybdenum, ruthenium and tin as substituted or coated metals are selected from the group consisting of hydroxides, nitrates, acetates, chlorides, carbonates, oxides and sulfates of each metal. Manufacturing method. The method according to claim 3 or 4, wherein the heat treatment step is performed under an air or oxygen atmosphere. A lithium secondary battery comprising the compound of claim 1, the compound prepared by the method of claim 3 or 4 as a cathode active material.