KR100794168B1 - Positive active material for lithium secondary battery, method of preparing thereof, and lithium secondary battery comprising the same - Google Patents

Abstract

An anode active material for a lithium secondary battery is provided to have thermal stability, inhibit decomposition of Ni, Co, and Mn upon charging and discharging of a battery, thereby improving life characteristics of a battery. An anode active material for a lithium secondary battery includes a lithium composite oxide represented by the formula of [Li_xM_yQ_z]_(3a)[Ni_mCo_nMn_t]_(3b)O_2, wherein M is at least one selected from the group consisting of alkali metals, alkali earth metals, and combinations thereof, Q is at least one selected from the group consisting of halogen, sulfur, phosphorous, and combinations thereof, 0.9<=x<=0.95, 0.04<=y<=0.06, 0.01<=z<=0.4, 0.1 <=m<=0.5, 0.01<=n<=0.5 0.005<=t<=0.5, and m+n+t=1.

Description

A positive electrode active material for a lithium secondary battery, a method of manufacturing the same, and a lithium secondary battery including the same TECHNICAL FIELD

1 is a cross-sectional view of a rectangular lithium secondary battery according to an embodiment of the present invention.

2 is an X-ray diffraction spectrum of the lithium composite metal oxide prepared in Examples 1 to 4.

3 is a differential scanning calorimetry graph of a coin battery prepared from lithium composite metal oxides prepared in Examples 1 to 3 and Comparative Example 1. FIG.

[Industrial use]

The present invention relates to a positive electrode active material for a lithium secondary battery, a method of manufacturing the same, and a lithium secondary battery including the same, and more particularly, has a thermally stable structure and can improve the life characteristics of a lithium secondary battery. It relates to a manufacturing method thereof and a lithium secondary battery comprising the same.

[Prior art]

Recently, with the trend toward miniaturization and light weight of portable electronic devices, the need for high performance and high capacity of batteries used as power sources for these devices is increasing.

 A battery generates power by using a material capable of electrochemical reactions at a positive electrode and a negative electrode. A typical example of such a battery is a lithium secondary battery that generates electric energy by a change in chemical potential when lithium ions are intercalated / deintercalated at a positive electrode and a negative electrode.

The lithium secondary battery is manufactured by using a material capable of reversible intercalation / deintercalation of lithium ions as a positive electrode and a negative electrode active material, and filling an organic electrolyte or a polymer electrolyte between the positive electrode and the negative electrode.

As a cathode active material of a lithium secondary battery, a lithium composite metal compound is used. Examples thereof include a composite of LiCoO ₂ , LiMn ₂ O ₄ , LiNiO ₂ , LiNi _{1- x} Co _x O ₂ (0 <x <1), and LiMnO ₂ . Metal oxides are being studied.

Among the cathode active materials, Mn-based cathode active materials such as LiMn ₂ O ₄ and LiMnO ₂ are easy to synthesize, are relatively inexpensive, have the best thermal stability compared to other active materials when overcharged, and are less attractive to the environment due to less pollution. However, it has a disadvantage of small capacity.

LiCoO ₂ exhibits good electron conductivity, high battery voltage, and excellent electrode characteristics, and is a representative cathode active material commercialized and marketed by Sony. However, it has the disadvantage of high price and low stability at high rate charge and discharge. In addition, LiNiO ₂ is the lowest of the above-mentioned positive electrode active material, exhibits the highest discharge capacity of the battery characteristics, but is difficult to synthesize and has the disadvantage of being the most structurally unstable during charge and discharge of the above-mentioned materials.

As described above, LiCoO ₂ and LiNiO ₂ have excellent electrochemical properties, but they are limited to 4.3 V, and at 4.5 V, capacity deterioration due to structural collapse occurs. In other words, when Li is released from LiNiO ₂ by charging, LiNiO ₂ becomes very unstable, and decomposition occurs at less than 200 ° C., whereas thermally it is very unstable. This is fatal when used as a positive electrode active material of a battery, and the generated oxygen induces thermal runaway of the battery, that is, ignition or rupture.

In order to solve this problem, a method of using an oxide in which Ni: Mn: Co is dissolved in a ratio of 1: 1: 1 has been proposed, but the positive electrode active material including these also greatly increases the decomposition reaction of Ni, Mn, and Co during battery charging and discharging. It could not be suppressed.

An object of the present invention for solving the above problems is to provide a positive electrode active material for a thermally stable lithium secondary battery.

Another object of the present invention is to provide a method for producing the cathode active material.

Still another object of the present invention is to provide a lithium secondary battery provided with a cathode including the cathode active material.

In order to achieve the above object, the present invention provides a cathode active material for a lithium secondary battery comprising a lithium composite oxide represented by the following formula (1):

[Formula 1]

[Li _x M _y Q _z ] _3a [Ni _m Co _n Mn _t ] _{3 b} O ₂

(In Formula 1, M is one selected from the group consisting of alkali metals, alkaline earth metals, and combinations thereof, Q is one selected from the group consisting of halogen, sulfur, phosphorus, and combinations thereof, and 0.9≤ x≤0.95, 0.04≤y≤0.06, 0.01≤z≤0.4, 0.1≤m≤0.5, 0.01≤n≤0.5 0.005≤t≤0.5, and m + n + t = 1)

In addition, the present invention

Lithium metal oxides including nickel, cobalt and manganese, metal salts containing M (M = alkaline metals, alkaline earth metals or combinations thereof), and compounds comprising Q (Q = halogen, sulfur, phosphorus or combinations thereof) Reacting by mixing; And

It provides a method for producing a cathode active material for a lithium secondary battery comprising a lithium composite metal oxide represented by the formula (1) comprising the step of quenching after heat-treating the compound obtained by the reaction.

In this case, quenching is performed at a rate of 700 ° C./min or more, preferably 700 to 1000 ° C./min, and most preferably 700 to 800 ° C./min.

In another aspect, the present invention provides a lithium secondary battery comprising a positive electrode active material containing a lithium composite oxide of the formula (1).

Hereinafter, the present invention will be described in more detail.

The lithium composite metal oxide of the present invention has a thermally stable structure by incorporating elements into a lithium site rather than a metal site through a quenching process after heat treatment, thereby improving life characteristics of a lithium secondary battery.

The lithium composite metal oxide is represented by the following Chemical Formula 1:

[Formula 1]

[Li _x M _y Q _z ] _3a [Ni _m Co _n Mn _t ] _{3 b} O ₂

(In Formula 1, M is one selected from the group consisting of alkali metals, alkaline earth metals, and combinations thereof, Q is one selected from the group consisting of halogen, sulfur, phosphorus, and combinations thereof, and 0.9≤ x≤0.95, 0.04≤y≤0.06, 0.01≤z≤0.4, 0.1≤m≤0.5, 0.01≤n≤0.5 0.005≤t≤0.5, and m + n + t = 1)

Preferably, M is one selected from the group consisting of Na, Mg, K, Ca, Rb, Sr, Cs, Ba, and combinations thereof, and more preferably Na or Mg. Hereinafter, M referred to throughout this specification includes the above element.

In addition, Q is one selected from the group consisting of halogen, sulfur, phosphorus, and combinations thereof, such as F. Q mentioned below throughout this specification includes the said element.

The lithium composite metal oxide has a layered rock salt structure in which the 3a site where Li is present, the 3b site where the metal is present, and oxygen are regularly arranged. At this time, the lithium composite metal oxide has a structure in which a part of Li present in the 3a site is substituted with M and Q.

A lithium composite metal oxide having a layered rock salt structure has a structure in which Li is present at a 3a site and a metal is present at a 3b site. For example, in the case of LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , Li is present at the 3a site, and Ni, Co, and Mn are present at the 3b site. However, the lithium-metal composite oxide having such a structure is left out the filling by _{Li LiNi 1/3 Co 1/} 3 Mn 1/3 O 2 The structure is very unstable, so that oxygen is separated at a low temperature, so that decomposition reactions are reduced to NiO, Cr ₂ O ₃ , MnO ₂ , or the like, and as a result, a battery may explode, ignite or rupture.

However, even when M and Q are substituted for some Li at 3a site as in the present invention, even when Li escapes, structural stabilization is suppressed to prevent the decomposition reaction, ignition or rupture of the battery.

The lithium composite metal oxide represented by Formula 1 is

Lithium metal oxides including nickel, cobalt and manganese, metal salts containing M (M = alkaline metals, alkaline earth metals or combinations thereof), and compounds comprising Q (Q = halogen, sulfur, phosphorus or combinations thereof) Reacting by mixing; And

After the heat treatment of the compound obtained by the reaction is prepared through a step of quenching.

First, a solvent is injected into the reactor, and then a lithium metal oxide including nickel, cobalt and manganese, a metal salt containing M (M = alkaline metal, alkaline earth metal or a combination thereof), and a compound containing Q (halogen, sulfur , Phosphorus or a combination thereof) are reacted by mixing.

The lithium metal oxide including nickel, cobalt and manganese is preferably represented by the following Chemical Formula 2:

[Formula 2]

LiNi _m Co _n Mn _t O ₂

(In Formula 2, 0.1≤m≤0.5, 0.01≤n≤0.5 0.005≤t≤0.5, and m + n + t = 1)

The lithium metal oxide of Chemical Formula 2 may be prepared and used directly by using a known method such as coprecipitation or a commercially available one.

The metal salt containing M may be a hydroxide, oxyhydroxide, nitrate, chloride, carbonate, acetate, oxalate, citrate, and combinations thereof including one metal selected from the group consisting of alkali metals, alkaline earth metals or combinations thereof. One selected from the group consisting of may be used, but is not limited thereto.

In addition, the compound containing Q may be a lithium compound containing one element selected from the group consisting of halogen, sulfur, phosphorus, and combinations thereof. Typically, one selected from the group consisting of LiF, LiP, Li ₃ P, LiP ₅ , LiP ₇ , Li ₂ S, and combinations thereof is possible.

At this time, the metal salt containing M and the compound containing Q are used by adjusting the stoichiometric ratio to satisfy the molar ratio of the formula (1).

As the solvent used, water or an alcohol selected from the group consisting of alcohols and mixed solvents thereof is used, and preferably water is used. In this case, the alcohol is preferably C1 to C4 lower alcohols selected from the group consisting of methanol, ethanol, isopropanol, and combinations thereof.

This reaction is preferably carried out at 150 ° C or less, preferably at 80 to 150 ° C for 60 to 180 minutes. If the reaction is carried out at a temperature lower than 80 ℃ can not achieve a homogeneous mixing, the reaction is not smooth, on the contrary, if the reaction is carried out in excess of 150 ℃ low boiling point of the solvent used is deep solvent evaporation is not preferable. In addition, if the reaction time is also less than 60 minutes can not achieve a sufficient reaction, if the reaction is carried out for more than 180 minutes a problem that the solvent used evaporates.

Next, the compound prepared through the reaction is quenched after heat treatment to prepare a lithium composite metal oxide represented by the formula (1).

The heat treatment is preferably an oxidizing atmosphere of air or oxygen for 1 to 5 hours at 700 to 1100 ℃.

At this time, the preliminary firing may be performed by maintaining at 250 to 650 ° C. for 5 to 15 hours before the heat treatment process.

The oxide obtained after the heat treatment is quenched to prepare a lithium composite metal oxide represented by Chemical Formula 1.

In this case, quenching is performed at a rate of 700 ° C./min or more, preferably 700 to 1000 ° C./min, and most preferably 700 to 800 ° C./min. This quenching causes a substitution reaction with a portion of Li present in the 3a site, not M and Q in the structure of Formula 1, but the metal present in the 3b site. In addition, the disordered structure at high temperature during or immediately after the heat treatment is not rearranged upon cooling, and maintains the disordered structure through quenching. If the quenching rate is less than or above the above range, M and Q cause a substitution reaction with the metal of the 3b site rather than the 3a site, thereby failing to obtain the effects described above.

The material produced through these steps is preferably used as a positive electrode active material of a lithium secondary battery.

The lithium secondary battery may include a positive electrode including a positive electrode active material; A negative electrode including a negative electrode active material; And an electrolyte present therebetween, wherein a lithium composite metal oxide according to the present invention is used as the cathode active material.

1 is a cross-sectional view of a rectangular lithium secondary battery according to an embodiment of the present invention. Referring to FIG. 1, a separator 6 is inserted between a positive electrode 2 and a negative electrode 4 to be wound up to form an electrode assembly 8, and then placed in a case 10. The top of the cell is sealed with a cap plate 12 and a gasket 14. The positive electrode tab 18 and the negative electrode tab 20 are respectively provided on the positive electrode 2 and the negative electrode 4 and the insulators 22 and 24 are inserted to prevent internal short circuit of the battery. The electrolyte 26 is injected before sealing the cell, and the injected electrolyte 26 is impregnated in the separator 6.

Although the figure shows a rectangular secondary battery, the lithium secondary battery of the present invention is not limited to this shape, and it is natural that any shape capable of operating as a battery such as a cylinder, a coin type, a pouch type, etc. is possible.

The positive electrode is prepared by mixing a positive electrode active material according to the present invention, a conductive material, a binder and a solvent to prepare a positive electrode active material composition, and then coating and drying the aluminum active material directly. Alternatively, the cathode active material composition may be cast on a separate support, and then the film obtained by peeling from the support may be manufactured by laminating on an aluminum current collector.

The conductive material is carbon black, graphite, metal powder, the binder is vinylidene fluoride / hexafluoropropylene copolymer, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polytetrafluoroethylene And mixtures thereof. In addition, N-methylpyrrolidone, acetone, tetrahydrofuran, decane, etc. are used as a solvent. In this case, the contents of the positive electrode active material, the conductive material, the binder, and the solvent are used at levels commonly used in lithium secondary batteries.

Like the positive electrode, the negative electrode is mixed with a negative electrode active material, a binder, and a solvent to prepare an anode active material composition, and the negative electrode active material film coated on the copper current collector or cast on a separate support and peeled from the support is coated on the copper current collector. It is prepared by lamination. At this time, the negative electrode active material composition may further contain a conductive material if necessary.

As the negative electrode active material, a material capable of intercalating / deintercalating lithium is used, and for example, lithium metal, lithium alloy, coke, artificial graphite, natural graphite, organic polymer compound combustor, carbon fiber, or the like is used. do. In addition, a conductive material, a binder, and a solvent are used similarly to the case of the positive electrode mentioned above.

The separator may be used as long as it is commonly used in lithium secondary batteries. For example, polyethylene, polypropylene, polyvinylidene fluoride or two or more multilayer films thereof may be used, and a polyethylene / polypropylene two-layer separator, It goes without saying that a mixed multilayer film such as polyethylene / polypropylene / polyethylene three-layer separator, polypropylene / polyethylene / polypropylene three-layer separator and the like can be used.

As the electrolyte to be charged in the lithium secondary battery, a non-aqueous electrolyte or a known solid electrolyte may be used, and a lithium salt is used.

Although the solvent of the said non-aqueous electrolyte is not specifically limited, Cyclic carbonates, such as ethylene carbonate, a propylene carbonate, butylene carbonate, vinylene carbonate; Chain carbonates such as dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate; Esters such as methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate and γ-butyrolactone; Ethers such as 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 1,2-dioxane and 2-methyltetrahydrofuran; Nitriles such as acetonitrile; Amides, such as dimethylformamide, etc. can be used. These can be used individually or in combination of two or more. In particular, a mixed solvent of cyclic carbonate and chain carbonate can be preferably used.

As the electrolyte, a gel polymer electrolyte in which an electrolyte solution is impregnated with a polymer electrolyte such as polyethylene oxide or polyacrylonitrile, or an inorganic solid electrolyte such as LiI or Li ₃ N can be used.

The lithium salt is LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, LiC ₄ F ₉ SO ₃ , LiSbF ₆ , LiAlO ₄ , LiAlCl ₄ , One selected from the group consisting of LiCl and LiI is possible.

Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

EXAMPLE

Positive electrode active material

(Example 1)

The reactor _{Ni 1/3 Co 1/3} Mn 1/3 (OH) 2 and LiOH · H ₂ O 1: at 400 ℃ then mixed in a molar ratio of 0.95, for 4 hours, and heat treated at 900 ℃ for 15 hours Li ₀ the lithium metal oxide of _{.95 Ni 1/3 Co 1/} 3 Mn 1/3 O 2 was prepared.

2 g of the lithium metal oxide prepared above, 0.1 g of Mg (OH) _{2, and} 0.1 g of LiF were uniformly mixed in an aqueous solution to react with the reactor.

The compound obtained by the reaction was heat-treated at 500 ° C. for 10 hours and then heat-treated at 1000 ° C. for 1 hour, and then quenched at a rate of 800 ° C./min to prepare a lithium composite metal oxide.

(Example 2)

The reactor _{Ni 1/3 Co 1/3} Mn 1/3 (OH) 2 and LiOH · H ₂ O 1: at 400 ℃ then mixed in a molar ratio of 0.95, for 4 hours, and heat treated at 900 ℃ for 15 hours Li ₀ the lithium metal oxide of _{.95 Ni 1/3 Co 1/} 3 Mn 1/3 O 2 was prepared.

2 g of the lithium metal oxide prepared above, 0.2 g of Mg (OH) _{2, and} 0.2 g of LiF were uniformly mixed in an aqueous solution to react with the reactor.

The compound obtained by the reaction was heat-treated at 500 ° C. for 10 hours and then heat-treated at 1000 ° C. for 1 hour, and then quenched at a rate of 800 ° C./min to prepare a lithium composite metal oxide.

(Example 3)

The reactor _{Ni 1/3 Co 1/3} Mn 1/3 (OH) 2 and LiOH · H ₂ O 1: at 400 ℃ then mixed in a molar ratio of 0.95, for 4 hours, and heat treated at 900 ℃ for 15 hours Li ₀ the lithium metal oxide of _{.95 Ni 1/3 Co 1/} 3 Mn 1/3 O 2 was prepared.

2 g of the lithium metal oxide prepared above, 0.1 g of NaOH, and 0.1 g of LiF were uniformly mixed in an aqueous solution to react with the reactor.

The compound obtained by the reaction was heat-treated at 300 ° C. for 10 hours and then heat-treated at 900 ° C. for 1 hour, and then quenched at a rate of 800 ° C./min to prepare a lithium composite metal oxide.

(Example 4)

The reactor _{Ni 1/3 Co 1/3} Mn 1/3 (OH) 2 and LiOH · H ₂ O 1: at 400 ℃ then mixed in a molar ratio of 0.95, for 4 hours, and heat treated at 900 ℃ for 15 hours Li ₀ lithium metal oxides _{.95 Ni 1/3 Co 1/} 3 Mn 1/3 O 2 was prepared.

2 g of the lithium metal oxide prepared above, 0.2 g of NaOH, and 0.2 g of LiF were reacted by uniformly mixing in an aqueous solution.

The compound obtained by the reaction was heat-treated at 300 ° C. for 10 hours and then heat-treated at 900 ° C. for 1 hour, and then quenched at a rate of 800 ° C./min to prepare a lithium composite metal oxide.

(Comparative Example 1)

The reactor _{Ni 1/3 Co 1/3} Mn 1/3 (OH) 2 and LiOH · H ₂ O 1: at 400 ℃ then mixed in a molar ratio of 0.95, for 4 hours, and heat treated at 900 ℃ for 15 hours Li ₀ the lithium metal oxide of _{.95 Ni 1/3 Co 1/} 3 Mn 1/3 O 2 was prepared.

Experimental Example 1

In order to determine the composition and structure of the lithium composite metal oxides prepared in Examples 1 to 4, ICP analysis, X-ray diffraction spectrum measurement, and Rietveld analysis were performed.

2 is an X-ray diffraction spectrum of the lithium composite metal oxide prepared in Examples 1 to 4. The X-ray diffraction spectrum results were used to confirm the structure of the lithium composite metal oxides prepared in Examples 1 to 4 through Rietveld analysis.

In addition to the above structure, the composition of the lithium composite metal oxide was confirmed through ICP analysis, and the structure and the composition of the lithium composite metal oxides prepared in Examples 1 to 4 are shown in Table 1 through ICP analysis and Rietveld analysis.

rescue Crystal structure Example 1 _{[Li 0 .94 Mg 0 .04 F} 0.02] 3a [Ni 1/3 Co 1/3 Mn 1/3] 3 b O 2 Layered rock salt structure Example 2 _{[Li 0 .90 Mg 0 .06 F} 0.02] 3a [Ni 1/3 Co 1/3 Mn 1/3] 3 b O 2 Layered rock salt structure Example 3 [Li Na _{0 .94 0 .04 0.02} F] _{3a [1} Ni _/ Co _{3 1/3} Mn _1/3] O _{2 3 b} Layered rock salt structure Example 4 _{[Li 0 .90 Na 0 .06 F} 0.02] 3a [Ni 1/3 Co 1/3 Mn 1/3] 3 b O 2 Layered rock salt structure

Referring to Table 1, it can be seen that in place of part of Li, Mg, Na, and F are substituted for 3a sites of the lithium composite metal oxides prepared in Examples 1 to 4. As a result, it can be seen that Mg and Na are present at the 3a site, not the 3b site, and F is also present at the 3a site and not the oxygen site due to the rapid cooling after the heat treatment.

Half cell

Coin-type batteries were manufactured using Examples 1 to 4 and the lithium composite metal oxide of Comparative Example 1 as a cathode active material.

First, a lithium composite metal oxide, super P (conductive material), and polyvinylidene fluoride (binder) were mixed in a weight ratio of 96/2/2 to prepare a composition for forming a positive electrode. The composition for forming an anode was coated on Al-foil to a thickness of 300 μm and then dried at 130 ° C. for 20 minutes. Then, the positive electrode plate was manufactured by rolling at a pressure of 1 ton.

A coin-type battery was manufactured by using the prepared positive electrode plate and lithium metal as counter electrodes. In this case, as the electrolyte, 1M LiPF ₆ dissolved in a solvent in which ethylene carbonate (EC) and dimethyl carbonate (DMC) were mixed in a 1: 1 volume ratio was used.

Experimental Example 2

The coin battery prepared above was charged and discharged (@ 40) in a voltage range of 3.0 to 4.3 V at room temperature (30 ° C.) using a charger and a discharger. The results obtained are shown in Table 2 below.

Initial charge capacity Initial discharge capacity Life Span (After 40 Times) Example 1 160 mAh / g 153 mAh / g 95% Example 2 155 mAh / g 150 mAh / g 94% Example 3 155 mAh / g 151 mAh / g 92% Example 4 155 mAh / g 151 mAh / g 92% Comparative Example 1 160 mAh / g 156 mAh / g 83%

Referring to Table 2, it can be seen that the battery using the lithium composite oxide of Examples 1 to 4, the initial capacity was equal or less than the battery of Comparative Example 1, but it is further improved in terms of life characteristics.

Experimental Example 3

After charging the coin battery prepared above to 4.5V, the battery was disassembled and the positive electrode mixture was taken out. Exothermic peak was measured using DSC (differential scanning calorimeter) as it was, and the obtained result is shown in FIG.

3 is a differential scanning calorimetry graph of a coin battery prepared from lithium composite metal oxides prepared in Examples 1 to 3 and Comparative Example 1. FIG.

Referring to FIG. 3, the coin battery made of the lithium composite metal oxide of Comparative Example 1 showed an exothermic peak at around 220 ° C. FIG. In comparison, the coin battery made of the lithium composite metal oxides prepared in Examples 1 to 3 of the present invention exhibited an exothermic peak at about 300 ° C., resulting in an exothermic onset temperature of 80 ° C. or more, and a rapid decrease in the amount of heat generated. have. These results indicate that the thermal stability of the lithium composite metal oxides prepared in Examples 1 to 3 is high.

All simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

The lithium composite metal oxide of the present invention has a thermally stable structure by incorporating elements into a lithium site rather than a metal site through a quenching process after heat treatment, thereby improving life characteristics of a lithium secondary battery.

Claims (15)

A cathode active material for a lithium secondary battery including a lithium composite oxide represented by Formula 1 below: [Formula 1] [Li _x M _y Q _z ] _3a [Ni _m Co _n Mn _t ] _{3 b} O ₂ (In Formula 1, M is one selected from the group consisting of alkali metals, alkaline earth metals and combinations thereof, Q is one selected from the group consisting of halogen, sulfur, phosphorus, and combinations thereof, and 0.9≤x ≤ 0.95, 0.04 ≤ y ≤ 0.06, 0.01 ≤ z ≤ 0.4, 0.1 ≤ m ≤ 0.5, 0.01 ≤ n ≤ 0.5 0.005 ≤ t ≤ 0.5, and m + n + t = 1) The method of claim 1, M is Na, Mg, K, Ca, Rb, Sr, Cs, Ba, and a positive electrode active material for a lithium secondary battery that is one selected from the group consisting of a combination thereof. The method of claim 1, Q is one type selected from the group consisting of florin (F), sulfur, phosphorus, and a combination thereof. Lithium metal oxides including nickel, cobalt and manganese, metal salts containing M (M = alkaline metals, alkaline earth metals or combinations thereof), and compounds comprising Q (Q = halogen, sulfur, phosphorus, or combinations thereof) Reacting by mixing); And Method of producing a positive electrode active material for a lithium secondary battery comprising a lithium composite oxide represented by the following formula (1) comprising the step of quenching after heat treatment the compound obtained by the reaction. [Formula 1] [Li _x M _y Q _z ] _3a [Ni _m Co _n Mn _t ] _{3 b} O ₂ (In Formula 1, M is one selected from the group consisting of alkali metals, alkaline earth metals and combinations thereof, Q is one selected from the group consisting of halogen, sulfur, phosphorus, and combinations thereof, and 0.9≤x ≤ 0.95, 0.04 ≤ y ≤ 0.06, 0.01 ≤ z ≤ 0.4, 0.1 ≤ m ≤ 0.5, 0.01 ≤ n ≤ 0.5 0.005 ≤ t ≤ 0.5, and m + n + t = 1) The method of claim 4, wherein M is Na, Mg, K, Ca, Rb, Sr, Cs, Ba, and a method for producing a positive electrode active material for a lithium secondary battery that is one selected from the group consisting of a combination thereof. The method of claim 4, wherein Wherein Q is one type selected from the group consisting of florin (F), sulfur, phosphorus, and combinations thereof. The method of claim 4, wherein The lithium metal oxide containing the nickel, cobalt and manganese is a method of producing a positive electrode active material for a lithium secondary battery is represented by the following formula (2): [Formula 2] LiNi _m Co _n Mn _t O ₂ (In Formula 2, 0.1≤m≤0.5, 0.01≤n≤0.5 0.005≤t≤0.5, and m + n + t = 1) The method of claim 4, wherein The metal salt containing M may be a hydroxide, oxyhydroxide, nitrate, chloride, carbonate, acetate, oxalate, citrate, and combinations thereof including one metal selected from the group consisting of alkali metals, alkaline earth metals or combinations thereof. Method for producing a positive active material for a lithium secondary battery which is one selected from the group consisting of. The method of claim 4, wherein The compound containing Q is a method for producing a positive electrode active material for a lithium secondary battery that is a lithium compound containing one element selected from the group consisting of halogen, sulfur, phosphorus, and combinations thereof. The method of claim 4, wherein The compound containing Q is LiF, LiP, Li ₃ P, LiP ₅ , LiP ₇ , Li ₂ S, and a method for producing a positive active material for a lithium secondary battery that is one selected from the group consisting of a combination thereof. The method of claim 4, wherein The heat treatment is a method of manufacturing a positive electrode active material for a lithium secondary battery that is carried out at 700 to 1100 ℃. The method of claim 4, wherein In addition, a preliminary firing is performed at 250 to 650 ° C. before the heat treatment. The method of claim 4, wherein The quenching is a method of manufacturing a cathode active material for a lithium secondary battery that is carried out at a rate of 700 ℃ / min or more. The method of claim 4, wherein The quenching is a method of manufacturing a cathode active material for a lithium secondary battery that is performed at a rate of 700 to 1000 ℃ / min. A positive electrode including a positive electrode active material; A negative electrode including a negative electrode active material; And an electrolyte present between them, A lithium secondary battery, wherein the cathode active material is the cathode active material according to any one of claims 1 to 3.

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