KR20060133615A - Cathode active material added with fluorine compound for lithium secondary batteries and method of producing thereof - Google Patents

Abstract

Provided are a positive electrode active material for a lithium secondary battery to improve the charge/discharge characteristics, lifetime characteristics, high voltage characteristics and high rate characteristics of a battery, and its preparation method. The positive electrode active material contains a fluorine compound in the form of a complex in a positive electrode active material. The method comprises the steps of adding a solution wherein F is dissolved to a fine powder element precursor solution of high dispersity to react it at 50-150 deg.C for 1-48 hours, thereby preparing a fluorine compound fine powder in the form of a complex having a high dispersity; drying the fluorine compound fine powder at 110 deg.C for 6-24 hours; heat treating the dried one at 150-900 deg.C for 1-20 hours under the oxidative or reductive condition or in vacuum; and adding 0.05-10 parts by weight of the heat treated one to 100 parts by weight of a positive electrode active material and mixing them uniformly.

Description

{Cathode active material added with fluorine compound for lithium secondary batteries And Method of producing}

       1 is a flow chart of a fluorine compound synthesis process according to Example 1 of the present invention.

Figure 2 is an XRD pattern of the fluorine compound synthesized in Example 1 of the present invention.

Figure 3 is a FE-SEM (Field Emission Scanning Electron Microscopy) photograph of the fluorine compound synthesized in Example 1 of the present invention.

4 is an XRD pattern of the positive electrode active material of Example 5 and Comparative Example 1 of the present invention.

5 is a field emission scanning electron microscopy (FE-SEM) photograph of the cathode active material of Example 5 of the present invention.

6 is a field emission scanning electron microscopy (FE-SEM) photograph of the cathode active material of Comparative Example 1 of the present invention.

       Figure 7 is a photograph of the results of Energy Dispersive Spectroscopy (EDS) of the positive electrode active material of Example 5 of the present invention.

FIG. 8 is a cycle curve of a half cell experimented at a voltage range of 3.0 to 4.5 mA and a constant current density of 0.2 mA / cm 2 at room temperature (30 ° C.) of Example 5 and Comparative Example 1 of the present invention. FIG.

FIG. 9 is a cycle curve of a half cell experimented at a voltage range of 3.0 to 4.5 and a room temperature (30 ° C.) constant current density of 0.8 mA / cm 2 of Example 5 and Comparative Example 1 of the present invention.

10 is a cycle curve of a half cell experimented in the voltage range of 3.0 to 4.5 V, 30 ℃, constant current density 0.2 mA / cm 2 of the positive electrode active material of Examples 5, 6, 7 and 8 and Comparative Example 1 of the present invention.

11 is an XRD pattern of the positive electrode active material of Example 9 and Comparative Example 2 of the present invention.

12 is a cycle curve of a half cell experimented at a voltage range of 2.8 to 4.5 kW and a constant current density of 0.2 mA / cm 2 at a positive electrode active material of Example 9 and Comparative Example 2 of the present invention.

FIG. 13 is a cycle curve of a half cell experimented at a voltage range of 2.8 to 4.5 kV and a constant current density of 0.8 mA / cm 2 at a positive electrode active material of Example 9 and Comparative Example 2 of the present invention. FIG.

14 is an XRD pattern of the positive electrode active material of Example 10 and Comparative Example 3 of the present invention.

15 is a cycle curve of a half cell experimented at a voltage range of 2.8 ~ 4.6 kW, a constant current density of 0.2 mA / cm ² of the positive electrode active material of Example 10 and Comparative Example 3 of the present invention.

FIG. 16 is a cycle curve of a half cell experimented at a voltage range of 2.8 to 4.6 kW and a constant current density of 0.8 mA / cm ² at a positive electrode active material of Example 10 and Comparative Example 3 of the present invention.

17 is an XRD pattern of the positive electrode active material of Example 11 and Comparative Example 4 of the present invention.

18 is a cycle curve of a half cell experimented at a voltage range of 2.8 to 4.6 kW and a constant current density of 0.2 mA / cm 2 at room temperature (30 ° C.) of Example 11 and Comparative Example 4 of the present invention.

19 is a cycle curve of a half cell experimented at a voltage range of 2.8 to 4.6 kW and a constant current density of 0.8 mA / cm 2 at room temperature of the positive electrode active materials of Example 11 and Comparative Example 4 of the present invention.

20 is an XRD pattern of the positive electrode active material of Example 12 and Comparative Example 5 of the present invention.

FIG. 21 is a cycle curve of a half cell tested at a voltage range of 3.0 to 4.5 kW and a constant current density of 0.2 mA / cm 2 at a positive electrode active material of Example 12 and Comparative Example 5 of the present invention. FIG.

FIG. 22 is a cycle curve of a half cell experimented at a voltage range of 3.0 to 4.5 mA and a constant current density of 0.8 mA / cm 2 at room temperature of Example 12 of the present invention and Comparative Example 5;

It is an object of the present invention to provide a method for preparing a cathode active material for a lithium secondary battery to which a synthesized additive, which has excellent life characteristics, high voltage characteristics, and the like, is added. More specifically, an object of the present invention is to improve the charge and discharge characteristics, life characteristics, high voltage characteristics and high rate characteristics of a battery by synthesizing a fluorine compound of a fine powder as an additive and adding it to a cathode active material for a lithium secondary battery.

The demand for secondary batteries, which are used for charging and discharging with portable electronic devices such as PDAs, mobile phones, notebook computers, and electric bicycles and electric vehicles, is rapidly increasing. In particular, since their product performance depends on secondary batteries, which are key components, the demand for high performance batteries is very large. The characteristics required for the battery have various aspects such as charge and discharge characteristics, lifespan, high rate characteristics, and stability at high temperatures. Lithium secondary batteries have the most attention due to their high voltage and high energy density.

Lithium secondary batteries are classified into lithium batteries using a negative electrode as a lithium metal and lithium ion batteries using an interlayer compound such as carbon that can be inserted and desorbed. Alternatively, depending on the electrolyte used, it may be classified into a liquid battery using a liquid, a gel polymer battery using a mixture of a liquid and a polymer, and a solid polymer battery using purely a polymer.

Commercially available small lithium ion _secondary batteries use LiCoO ₂ for the positive electrode and carbon for the negative electrode. Japan Moly Energy uses LiMn ₂ O ₄ as its anode, but its use is negligible compared to LiCoO ₂ . LiNiO ₂ , LiCo _x Ni _1-x O ₂ and LiMn ₂ O ₄ are the anode materials currently being actively researched and developed. LiCoO ₂ is an excellent material having stable charging and discharging characteristics, excellent electronic conductivity, high thermal stability, and flat discharge voltage characteristics. However, CoCo has low reserves, is expensive, and toxic to humans. LiNiO ₂ is not commercialized due to difficulty in material synthesis and thermal stability, and LiMn ₂ O ₄ is commercialized in low cost. However, LiMn ₂ O ₄ with a spinel structure has a theoretical capacity of 148 mAh / g, which is smaller than other materials, and has a three-dimensional tunnel structure. It is lower than LiCoO ₂ and LiNiO ₂ and has poor cycle characteristics due to the Jahn-Teller effect. In particular, the high temperature property at 55 ℃ or more is poor compared to LiCoO ₂ and is not widely used in the actual battery.

Therefore, much research has been conducted on materials having a layered crystal structure as a material capable of overcoming the above problems. Among these, Li [Ni _1/2 Mn _1/2 ] O ₂ and Li [Ni _{1/3 in} which nickel-manganese and nickel-cobalt-manganese are mixed 1: 1 in each of the most popular layered crystal structures. Co _1/3 Mn _1/3 ] O _2, etc. may be mentioned. These materials exhibit lower cost, higher capacity and better thermal stability than LiCoO ₂ .

However, these materials have poor high-rate and low-temperature characteristics due to their low electron conductivity compared to LiCoO ₂ , and their energy density does not improve despite the high capacity due to low tap density. In particular, in the case of Li [Ni _1/2 Mn _1/2 ] O ₂ , the electrical conductivity is very low, which makes it difficult to put it to practical use (J. of Power Sources, 112 (2002) 41-48). In particular, the high-power characteristics of these materials are less than LiCoO ₂ or LiMn ₂ O ₄ for use as hybrid power sources for electric vehicles. In order to solve this problem, a method of treating conductive carbon black (Japanese Patent Laid-Open No. 2003-59491) has been proposed, but many improvements have not been reported.

Lithium secondary batteries have a problem in that their lifespan drops rapidly as they are repeatedly charged and discharged. This problem is particularly acute at high temperatures. This is due to a phenomenon in which the electrolyte is decomposed or the active material is deteriorated due to moisture or other effects in the battery, and the internal resistance of the battery is increased. Many efforts have been made to solve this problem. Techniques for improving energy density and high rate characteristics by adding TiO ₂ to LiCoO ₂ active materials have been studied (Electrochemical and Solid-State Letters, 4 (6) A65-A67 2001). In addition, US Patent No. 5,709,968 is a method to prevent the overcharge current and the resulting thermal runaway phenomenon by adding a benzene compound, US Patent No. 5,879,834 is a method for improving the stability of the battery by adding a small amount of aromatic compounds, Korean published Patent Publication No. 2003-0061219 reports a technique for improving performance by mixing a compound in a direct electrolyte solution, such as adding cyclohexylbenzene to improve the chemical stability. However, it is not yet completely solved the problem of deterioration of life or the generation of gas due to decomposition of the electrolyte during charging and discharging. In addition, a phenomenon in which an active material is dissolved by an acid generated by oxidation of an electrolyte during charging is introduced as a cause of a decrease in capacity of a battery (Journal of Electrochemical Society, 143 (1996) P2204). Recently, LiF is added to synthesize Li [Ni _x Co _1-2x Mn _x ] O ₂ to reduce the reaction with the electrolyte at high temperatures and to improve the electrochemical performance (Journal of Electrochemical Society, 151). (2004) A1749-A1754.

     In order to solve the problem of deterioration of the battery performance as described above, the present invention is prepared by adding a positive electrode active material additive for a lithium secondary battery to the positive electrode active material to produce a positive electrode active material for lithium secondary battery performance is reduced in the battery life characteristics, in particular high pressure and high rate It aims to prevent the phenomenon.

In order to achieve the above object, in the present invention, a lithium secondary battery cathode active material is provided in which a fluorine compound in a complex salt form is added to a cathode active material.

The fluorine compound is CsF, KF, LiF, NaF, RbF, TiF, AgF, AgF₂, BaF ₂ , CaF ₂ , CuF ₂ , CdF ₂ , FeF ₂ , HgF ₂ , Hg ₂ F ₂ , MnF ₂ , MgF ₂ , NiF ₂ , PbF ₂ , SnF ₂ , SrF ₂ , XeF ₂ , ZnF ₂ , AlF ₃ , BF ₃ , BiF ₃ , CeF ₃ , CrF ₃ , DyF ₃ , EuF ₃ , GaF ₃ , GdF ₃ , FeF ₃ , HoF ₃ , _{InF 3, LaF 3, LuF 3} , MnF 3, NdF 3, VOF 3, PrF 3, SbF 3, ScF 3, SmF 3, TbF 3, TiF 3, TmF 3, YF 3, YbF 3, TIF 3, CeF 4 _{, GeF 4, HfF 4, SiF} 4, SnF 4, TiF 4, VF 4, ZrF 4, NbF 5, SbF 5, TaF 5, BiF 5, MoF 6, ReF 6, the group with fluorine consisting of SF ₆ and WF ₆ It is characterized in that any one or more selected from all compounds containing.

The positive electrode active material to which the fluorine compound is added is Li _{1 + a} [Co _1-x M _x ] O _2-b N _b having a hexagonal layered rock salt structure (0.01 ≦ a ≦ 0.2, 0.01 ≦ _b ≦ 0.2, 0.01 ≦ x≤0.1, M = Mg, Al, Ni, Mn, Zn, Fe, Cr, Ga, Mo and W at least one metal selected from the group, N is F or S), Li having a hexagonal layered rock salt structure _{1 + a} [Ni _1-x M _x ] O _2-b N _b (0.01 ≦ a ≦ 0.2, 0.01 ≦ _b ≦ 0.2, 0.01 ≦ x ≦ 0.5, M = Mg, Al, Co, Mn, Zn, Fe, At least one metal selected from the group consisting of Cr, Ga, Mo, W, N is F or S), Li _{1 + a} [Ni _1-xy Co _x Mn _y ] O _2-b having a hexagonal layered rock salt structure N _b (0.01 ≦ a ≦ 0.2, 0.01 ≦ _b ≦ 0.1, 0.05 ≦ x ≦ 0.3, 0.1 ≦ y ≦ 0.35, 0.15 ≦ x + y ≦ 0.6, N is F or S), Li having a hexagonal layered rock salt structure [Li _a (Ni _x Co _1-2x Mn _x ) _1-a ] O _2-b N _b (0.01≤a≤0.2, 0.01≤x≤0.5, 0.01≤b≤0.1, N is F or S), hexagonal Li [Li _a (Ni _x Co _1-2x Mn _{xy / 2} M _y ) _1-a ] O _{2 -b} N _b (M = Mg, Ca, Cu, Zn at least one metal selected from the group consisting of, 0.01≤a≤0.2, 0.01≤x≤0.5, 0.01≤y≤0.1, 0.01≤b≤0.1, N is F or S), Li [Li _a (Ni _1/3 Co _{(1 / 3-2x)} Mn _{( 1/3 + x)} M _x ) _1-a ] O _{2-b with} hexagonal layered rock salt structure N _b (at least one metal selected from the group consisting of M = Mg, Ca, Cu, Zn, 0.01 ≦ a ≦ 0.2, 0.01 ≦ x ≦ 0.5, 0.01 ≦ y ≦ 0.1, 0.01 ≦ bV0.1, N is F or S), consisting of Li [Li _a (Ni _x Co _1-2x-y Mn _x M _y ) _1-a ] O _2-b N _b (M = B, Al, Fe, Cr) with hexagonal layered rock salt structure At least one metal selected from the group, 0.01 ≦ a ≦ 0.2, 0.01 ≦ x ≦ 0.5, 0.01 ≦ y ≦ 0.1, 0.01 ≦ b ≦ 0.1, N is F or S), Li [Li _a having a hexagonal layered rock salt structure (Ni _x Co _1-2x-y Mn _{xz / 2} M _y N _z ) _1-a ] O _2-b N _b (M = B, at least one metal selected from the group consisting of Al, Fe, Cr, N = Mg or Ca, 0.01≤a≤0.2, 0.01≤x≤0.5, 0.01≤y≤0.1, 0.01≤b≤0.1, N is F or S), LiM _x Fe _1-x PO ₄ having an olivine structure (M = Co, Ni, Mn at least one metal selected from the group consisting of, 0≤x≤1), having a cubic structure Spinel Li _{1 + a} [Mn _2-x M _x ] O _4-b N _b (0.01 ≦ a ≦ 0.15, 0.01 ≦ _b ≦ 0.2, M = Co, Ni, Cr, Mg, Al, Zn, Mo, W 0.01 ≤ x ≤ 0.1, N is F or S) and spinel Li _{1 + a} having a cubic structure [Ni _0.5 Mn _1.5-x M _x ] O _4-b N _b (0.01 ≦ a ≦ 0.15, 0.01 ≦ _b ≦ 0.2, 0.01 ≦ x ≦ 0.1, M = Co, Ni, Cr, Mg, Al, Zn, Mo, W and at least one metal selected from the group, N is characterized in that any one of F or S).

In the present invention, a solution of fluorine (F) is added to a highly dispersed fine powder element precursor solution, and reacted at 50 ° C. to 150 ° C. for 1 to 48 hours to form a highly dispersed fine powder fluorine compound. Thereafter, the formed fine powder fluorine compound is dried at 110 ° C. for 6 to 24 hours, and then heat treated at 150 ° C. to 900 ° C. for 1 to 20 hours under any one of an oxidizing atmosphere, a reducing atmosphere, and a vacuum state to form a fine powder fluorine compound. After the preparation, a method for producing a cathode active material for a lithium secondary battery, characterized in that uniform mixing by adding 0.05 to 10 parts by weight of the fine powder fluorine compound relative to 100 parts by weight of the cathode active material for lithium secondary batteries.

The element precursor solution is used in a concentration of 0.1 to 3M, the solution in which fluorine (F) is dissolved is reacted for 1 to 48 hours at 50 ℃ to 150 ℃ using a 0.1 to 18 M concentration of fine dispersion of complex salt form It is characterized by forming a powdered fluorine compound.

The element precursors include Cs, K, Li, Na, Rb, Ti, Ag (I), Ag (II), Ba, Ca, Cu, Cd, Fe, Hg (II), Hg (I), Mn (II) , Mg, Ni, Pb, Sn, Sr, Xe, Zn, Al, B, Bi (III), Ce (III), Cr, Dy, Eu, Ga, Gd, Fe, Ho, In, La, Lu, Mn (III), Nd, VO, Pr, Sb (III), Sc, Sm, Tb, Ti (III), Tm, Y, Yb, TI, Ce (IV), Ge, Hf, Si, Sn, Ti (IV ), V, Zr, Nb, Sb (V), Ta, Bi (V), Mo, Re, S and W alkoxide salts, sulfates, nitrates, acetates, chlorides of at least one element selected from the group consisting of It is characterized by any one of phosphate compounds.

A solution in which fluorine (F) is dissolved to precipitate the elemental precursor in the form of a complex salt is a compound capable of providing fluorine (F) to precipitate the elemental precursor, such as NH ₄ F, HF, and A (Anhydrous) HF, in the form of a complex salt. It is characterized in that the solution of at least one compound selected from the group.

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

The present invention relates to a cathode active material for a lithium secondary battery formed by forming a fine powder fluorine compound and adding it to the cathode active material in order to prevent the life characteristics of the lithium secondary battery, in particular, the performance degradation at high pressure and high rate.

In the production method of the present invention synthesizes a fine powder fluorine compound to be used as an additive of the positive electrode active material for lithium secondary batteries, the fluorine compound to be synthesized is CsF, KF, LiF, NaF, RbF, TiF, AgF, AgF₂, BaF ₂ , CaF ₂ , CuF ₂ , CdF ₂ , FeF ₂ , HgF ₂ , Hg ₂ F ₂ , MnF ₂ , MgF ₂ , NiF ₂ , PbF ₂ , SnF ₂ , SrF ₂ , XeF ₂ , ZnF ₂ , AlF ₃ , BF ₃ , BiF ₃ , _{CeF 3, CrF 3, DyF 3} , EuF 3, GaF 3, GdF 3, FeF 3, HoF 3, InF 3, LaF 3, LuF 3, MnF 3, NdF 3, VOF 3, PrF 3, SbF 3, ScF 3 , SmF ₃ , TbF ₃ , TiF ₃ , TmF ₃ , YF ₃ , YbF ₃ , TIF ₃ , CeF ₄ , GeF ₄ , HfF ₄ , SiF ₄ , SnF ₄ , TiF ₄ , VF ₄ , ZrF ₄ , NbF ₅ , SbF _{5, TaF 5, BiF 5,} MoF 6, ReF 6, there is more than one from any compound containing the group consisting of fluorine and SF ₆ and WF ₆ can be selected.

The surface of the fine powder fluorine compound of the present invention is amorphous, crystalline, or a mixture of crystalline and amorphous.

In the present invention, as a preferred method for preparing a fine powder fluorine compound, which is a positive electrode active material additive for a lithium secondary battery, a solution in which fluorine (F) is dissolved is added to a high powder fine powder element precursor solution, and is then subjected to 1 to 48 hours at 50 ° C to 150 ° C. After the reaction to form a high-dispersity fine powder fluorine compound in the form of a complex salt, the formed fine powder fluorine compound is dried for 6 to 24 hours at 110 ℃, then oxidizing atmosphere, reducing for 1 to 20 hours at 150 ℃ to 900 ℃ The heat treatment may be performed under any one of an atmosphere and a vacuum to provide a fine powder fluorine compound. The reason for raising the coprecipitation reaction temperature is that the coprecipitation of the element precursor can obtain a highly dispersed precipitate in the form of a complex salt at a high temperature.

  As described above, when a solution containing fluorine (F) is mixed with a solution in which the element precursor is dissolved, a fine powder fluorine compound is formed after a predetermined time, and the formed fine powder fluorine compound is heat-treated as a cathode active material additive for a lithium secondary battery. Can be used. Since the fluorine compound is formed by mixing the element precursor solution and the solution containing fluorine (F), it is not necessary to adjust the precipitation rate when adding the solution containing fluorine (F). In addition, since the fluorine compound is formed by mixing the element precursor and fluorine (F) in advance, the amount of solvent used can be reduced. For example, since the solvent used is a reagent that is more expensive than distilled water in the case of alcohol and ether alcohol, reducing the amount of solvent can reduce the cost in the fluorine compound synthesis process.

Specifically, the Cs, K, Li, Na, Rb, Ti, Ag (I), Ag (II), Ba, Ca, Cu, Cd, Fe, Hg (II), Hg (I), Mn (II), Mg, Ni, Pb, Sn, Sr, Xe, Zn, Al, B, Bi (III), Ce (III), Cr, Dy, Eu, Ga, Gd, Fe, Ho, In, La, Lu, Mn (III), Nd, VO, Pr, Sb (III), Sc, Sm, Tb, Ti (III), Tm, Y, Yb, TI, Ce (IV), Ge, Hf, Si, Sn, One or more elemental precursors consisting of Ti (IV), V, Zr, Nb, Sb (V), Ta, Bi (V), Mo, Re, S, and W may be selected from alcohol solutions such as methanol, ethanol and isopropanol or ethylene. After dissolving in distilled water or an ether solution such as glycol and butyl glycol, a solution containing fluorine (F) is mixed to form a fine powder fluorine compound.

At this time, the element precursor solution to be used is used in the concentration of 0.1 to 3M, the solution containing fluorine (F) is preferably used in the concentration of 0.1 to 18M. As the element precursor, an alkoxide salt such as methoxide, ethoxide, isopropoxide and butoxide, or sulfate, nitrate, acetate, chloride, or oxide salt may be used. In addition, the solution containing fluorine (F) to precipitate the element precursor in the form of a complex salt may be used that contains fluorine (F), such as NH ₄ F, HF, A (Anhydrous) HF. The element precursor solution and the solution containing fluorine (F) are mixed and reacted at 50 ° C. to 150 ° C. for 1 to 48 hours.

Another method will be described in detail, by adding a solution containing fluorine (F) at a constant rate to a solution in which the highly dispersed fine powder element precursor is dissolved, and reacting at 50 to 150 ° C. for 1 to 48 hours to form a complex salt. There is provided a method for producing a fine powder fluorine compound, characterized in that to form a fine powder fluorine compound. The reason for raising the coprecipitation reaction temperature is that the coprecipitation of the element precursor can obtain a highly dispersed precipitate in the form of a complex salt at a high temperature.

As described above, when the fluorine compound is formed by mixing the element precursor and fluorine (F), the fluorine compound generated due to the characteristics of the element precursor does not form a fine powder of high dispersion, and agglomerates with each other. When forming, even if added to the positive electrode active material may not see the effect of improving the characteristics. Therefore, in this case, as described above, it is preferable to add a solution containing fluorine (F) at a constant rate to control the precipitation rate so that the fluorine compound is formed in the form of fine powder of high dispersion.

First Cs, K, Li, Na, Rb, Ti, Ag (I), Ag (II), Ba, Ca, Cu, Cd, Fe, Hg (II), Hg (I), Mn (II), Mg , Ni, Pb, Sn, Sr, Xe, Zn, Al, B, Bi (III), Ce (III), Cr, Dy, Eu, Ga, Gd, Fe, Ho, In, La, Lu, Mn (Ⅲ ), Nd, VO, Pr, Sb (III), Sc, Sm, Tb, Ti (III), Tm, Y, Yb, TI, Ce (IV), Ge, Hf, Si, Sn, Ti (IV), One or more element precursors consisting of a group of V, Zr, Nb, Sb (V), Ta, Bi (V), Mo, Re, S, W may be used, for example, an alcohol solution such as methanol, ethanol, and isopropanol or ethylene glycol. After dissolving in ether solution such as butyl glycol and distilled water, a solution containing fluorine (F) is added at a constant rate to form a fine powder fluorine compound of high dispersion.

At this time, the element precursor solution to be used is used in the concentration of 0.1 to 3M, the solution containing fluorine (F) is preferably used in the concentration of 0.1 to 18M. As the element precursor, an alkoxide salt such as methoxide, ethoxide, isopropoxide and butoxide, or sulfate, nitrate, acetate, chloride, or oxide salt may be used. In addition, fluorine (F) such as NH ₄ F, HF, and A (Anhydrous) HF, which may provide fluorine (F), may be used to precipitate the element precursor in a complex salt form. The solution containing (F) was added at a constant rate and reacted at 50 ° C. to 150 ° C. for 1 to 48 hours.

In the present invention, the formed fine powder fluorine compound is dried for 6 to 24 hours at 110 ℃, and further heat treatment under any one of oxidizing atmosphere, reducing atmosphere and vacuum for 1 to 20 hours at 150 ℃ to 900 ℃ lithium secondary It can be used as a positive electrode active material additive for batteries, and this heat treatment process removes impurities that could not be removed to make a desired fine powder fluorine compound form.

By adding the synthesized fine powder fluorine compound to reduce the influence on the acid generated near the positive electrode active material, or by suppressing the reactivity of the positive electrode active material and the electrolyte, it is possible to improve the phenomenon that the capacity of the battery is sharply reduced A cathode active material having improved discharge characteristics, lifespan characteristics, high voltage, and high rate characteristics can be provided.

       In the present invention, as a preferred method for producing a cathode active material for a lithium secondary battery to which the synthesized fine powder fluorine compound is added, a fluorine compound is uniformly mixed with a lithium secondary battery cathode active material and a fine powder fluorine compound of 0.05 to 10% by weight relative to the cathode active material. An added positive electrode active material for a lithium secondary battery is prepared.

       In the present invention, the fine powder fluorine compound is further heat-treated in any one of an oxidizing atmosphere, a reducing atmosphere and a vacuum state for 1 to 20 hours at 150 ℃ to 600 ℃ mixed fine powder fluorine compound synthesized uniformly It can be used as a positive electrode active material for a lithium secondary battery, which increases the bonding strength of the fluorine compound and the positive electrode active material through this heat treatment process.

Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these Examples.

Example 1

1. Preparation of AlF ₃

After dissolving 0.25 M Al (NO ₃ ) ₃ .9H ₂ O in 100 ml distilled water in a 500 ml beaker, a 0.75 M NH ₄ F 100 ml solution was prepared and the reactor temperature was maintained at about 80 ° C., followed by 1 ml The mixture was mixed at a flow rate of / min, and stirred for 12 hours after the coprecipitation reaction. The average temperature of the reactor was maintained at about 80 ° C. The higher coprecipitation reaction temperature is because the coprecipitation of AlF ₃ can obtain a highly dispersed precipitate in the form of a complex salt at a high temperature. The fluorine compound thus obtained was washed several times with distilled water, dried in a 110 ° C. warm air bath for 12 hours, and then heat-treated at 400 ° C. under inert atmosphere to prepare AlF ₃ .

2. Characterization of AlF ₃

i) XRD

The prepared AlF ₃ was measured using an X-ray diffraction analyzer (trade name: Rint-2000, company name: Rigaku, Japan), and the X-ray diffraction pattern was measured and shown in FIG. 2.

ii) Scanning Electron Microscopy

A SEM (trade name: JSM 6400, company name: JEOL, Japan) photograph of AlF ₃ prepared in the method of Example 1 is shown in FIG. 3.

3. Preparation of LiCoO ₂ with AlF ₃

AlF ₃ prepared in the cathode active material LiCoO ₂ for a lithium secondary battery that is commercially available and used 2 mol% of the positive electrode active material was added and uniformly mixed to prepare LiCoO ₂ to which AlF ₃ was added.

4. Characterization of LiCoO ₂ with AlF ₃

i) XRD

LiCoO ₂ to which AlF ₃ was added was measured using an X-ray diffractometer (trade name: Rint-2000, company name: Rigaku, Japan), and the X-ray diffraction pattern was measured and shown in FIG. 4.

ii) Scanning Electron Microscopy

The SEM (trade name: JSM 6400, company name: JEOL, Japan) photograph of the prepared AlF ₃ added LiCoO ₂ is shown in FIG. 5.

Iii) Energy Dispersive Spectroscopy (EDS)

The EDS (trade name: JSM 6400, company name: JEOL, Japan) photograph of the prepared AlF ₃ added LiCoO ₂ is shown in FIG. 7. Al and F were evenly mixed.

5. Manufacture of Anode

In order to prepare a positive electrode with LiCoO ₂ added with AlF ₃ of the present invention, 20 mg of LiCoO ₂ to which AlF ₃ was added, 8 mg of Teflonized acetylene black, and 4 mg of graphite (graphite) Was mixed uniformly. The mixture was uniformly compressed at a pressure of 1 ton using stainless ex-met and dried at 130 ° C. to prepare a cathode for a lithium secondary battery.

6. Manufacturing of coin cell

The prepared anode and lithium foil were used as counter electrodes, and a porous polyethylene membrane (Celgard ELC, Celgard 2300, thickness: 25 µm) was used as a separator, and ethylene carbonate: dimethyl carbonate = 1: 1 (volume ratio) mixed solvent. A coin cell of the 2032 standard was prepared according to a conventional manufacturing process of a lithium battery using a 1 mol LiPF ₆ solution of.

In order to evaluate the characteristics of the prepared battery, using an electrochemical analyzer (manufactured by Toyo, Toscat3000U, Japan) at room temperature (30 ° C.), a potential region of 3.0 to 4.5 V, and 0.2 mA / cm 2 Charge and discharge experiments were carried out at a current density of 0.8 mA / cm 2. The capacity according to the cycle is shown in FIGS. 8 to 9. In case of LiCoO ₂ with AlF ₃ added, the 50% cycle is maintained at room temperature (30 ℃), 94.4% at 0.2mA / cm2 and 89% at 0.8mA / cm2. Was

Example 2

1. Preparation of ZrF ₄

After dissolving 0.25 M ZrO (NO ₃ ) ₂ .2H ₂ O in a 500 ml beaker in 100 ml of distilled water, a 100 ml solution of ₁ M NH ₄ F was prepared and the reactor temperature was maintained at about 80 ° C., followed by 1 ml / The mixture was mixed at a flow rate of min and stirred for 12 hours after the coprecipitation reaction. The average temperature of the reactor was maintained at about 80 ° C. The increase in the coprecipitation temperature is because the coprecipitation of ZrF ₄ can obtain a highly dispersed precipitate in the form of a complex salt at a high temperature. The fluorine compound thus obtained was washed several times with distilled water, dried in a 110 ° C. warm air bath for 12 hours, and then heat-treated in an inert atmosphere to prepare ZrF ₄ .

2. Preparation of LiCoO ₂ with ZrF ₄

ZrF ₄ prepared in the positive electrode active material LiCoO ₂ for a lithium secondary battery which is commercially available and used 2 mol% of the positive electrode active material was added and uniformly mixed to prepare LiCoO ₂ to which ZrF ₄ was added.

3. Manufacturing and Characterization of Coin Battery

The positive electrode was manufactured in the same manner as in Example 1 using LiCoO ₂ to which ZrF ₄ was added, and a coin battery including the same was prepared.

In order to evaluate the characteristics of the manufactured coin battery, the electrochemical analyzer (manufactured by Toyo, Toscat3000U, Japan) was used at 30 ° C., 3.0 to 4.5 V potential region, and 0.2 mA / cm 2 current density condition. Discharge experiments were made. The capacity according to the cycle is shown in FIG. 10. In the manufactured battery, the capacity was decreased according to the cycle number.

Example 3

1. Preparation of MgF ₂

After dissolving 0.25 M of Mg (NO ₃ ) ₂ .6H ₂ O in a 500 ml beaker in 100 ml of distilled water, a 100 ml solution of 0.5 M NH ₄ F was prepared and the reactor temperature was maintained at about 80 ° C., followed by 1 ml The mixture was mixed at a flow rate of / min, and stirred for 12 hours after the coprecipitation reaction. The average temperature of the reactor was maintained at about 80 ° C. The increase in the coprecipitation temperature is because the coprecipitation of MgF ₂ can obtain a highly dispersed precipitate in the form of a complex salt at a high temperature. The fluorine compound thus obtained was washed several times with distilled water, dried in a 110 ° C. warm air bath for 12 hours, and heat-treated under an inert atmosphere to prepare MgF ₂ .

2. Preparation of LiCoO ₂ with MgF ₂

MgF ₂ prepared in the cathode active material LiCoO ₂ for a lithium secondary battery that is commercially available and used 2 mol% of the positive electrode active material was added and uniformly mixed to prepare LiCoO ₂ to which MgF ₂ was added.

3. Manufacturing and Characterization of Coin Battery

A positive electrode was prepared in the same manner as in Example 1 using LiCoO ₂ to which MgF ₂ was added by the above method, and a coin battery including the same was prepared.

In order to evaluate the characteristics of the manufactured coin battery, the electrochemical analyzer (manufactured by Toyo, Toscat3000U, Japan) was used at 30 ° C., 3.0 to 4.5 V potential region, and 0.2 mA / cm 2 current density condition. Discharge experiments were made. The capacity according to the cycle is shown in FIG. 10. In the manufactured battery, the capacity was decreased according to the cycle number.

Example 4

1. Preparation of ZnF ₂

After dissolving 0.25 M Zn (NO ₃ ) ₂ .2H ₂ O in a 500 ml beaker in 100 ml of distilled water, a 100 ml solution of 0.5 M NH ₄ F was prepared and the reactor temperature was maintained at about 80 ° C., followed by 1 ml The mixture was mixed at a flow rate of / min, and stirred for 12 hours after the coprecipitation reaction. The average temperature of the reactor was maintained at about 80 ℃. The higher coprecipitation reaction temperature is because the coprecipitation of ZnF ₂ can obtain a highly dispersed precipitate in the form of a complex salt at a high temperature. The fluorine compound thus obtained was washed several times with distilled water, dried in a 110 ° C. warm air bath for 12 hours, and then heat-treated in an inert atmosphere to prepare ZnF ₂ .

2. Preparation of LiCoO ₂ with ZnF ₂

ZnF ₂ prepared in the cathode active material LiCoO ₂ for a lithium secondary battery that is commercially available and used 2 mol% of the positive electrode active material was added and uniformly mixed to prepare LiCoO ₂ to which ZnF ₂ was added.

3. Manufacturing and Characterization of Coin Battery

A positive electrode was prepared in the same manner as in Example 1 using LiCoO ₂ to which ZnF ₂ was added, and a coin battery including the same was prepared.

In order to evaluate the characteristics of the manufactured coin battery, the electrochemical analyzer (manufactured by Toyo, Toscat3000U, Japan) was used at 30 ° C., 3.0 to 4.5 V potential region, and 0.2 mA / cm 2 current density condition. Discharge experiments were made. The capacity according to the cycle is shown in FIG. 10. In the manufactured battery, the capacity was decreased according to the cycle number.

Example 5

LiNi _0.5 Mn _0.5 O ₂ to which AlF ₃ was added and evaluated in the same manner as in Example 1, and then a battery was prepared using LiNi _0.5 Mn _0.5 O ₂ to which AlF ₃ was added. In order to evaluate the characteristics of the manufactured coin cell, a potential range of 30 ° C., 2.8 to 4.5 V, and 0.2 mA / cm 2 and 0.8 mA / cm 2 using an electrochemical analyzer (Toscat3000U, Japan) Charging and discharging experiments were conducted under current density conditions of. The capacity according to the cycle is shown in FIGS. 12 to 13. In the manufactured battery, the capacity was decreased according to the cycle number.

Example 6

LiNi _1/3 Co _1/3 Mn _1/3 O ₂ to which AlF ₃ was added in the same manner as in Example 1, and after evaluating characteristics, LiNi _1/3 Co _1/3 Mn to which AlF ₃ was added _A battery was prepared using _{1 /} 3O ₂ . In order to evaluate the characteristics of the manufactured coin cell, a potential range of 30 ° C., 2.8 to 4.6 V, and 0.2 mA / cm 2 using an electrochemical analyzer (manufactured by Toyo, Toscat3000U, Japan) Charge and discharge experiments were carried out at a current density of 0.8 mA / cm 2. The capacity according to the cycle is shown in FIGS. 15 to 16. In the manufactured battery, the capacity was decreased according to the cycle number.

Example 7

LiNi _0.4 Co _0.2 Mn _0.4 O ₂ to which AlF ₃ was added and evaluated in the same manner as in Example 1, and then a battery was prepared using LiNi _0.4 Co _0.2 Mn _0.4 O ₂ to which AlF ₃ was added. . In order to evaluate the characteristics of the manufactured coin cell, a potential range of 30 ° C., 2.8 to 4.6 V, and 0.2 mA / cm 2 using an electrochemical analyzer (manufactured by Toyo, Toscat3000U, Japan) Charge and discharge experiments were carried out at a current density of 0.8 mA / cm 2. The capacity according to the cycle is shown in FIGS. 18 to 19. In the manufactured battery, the capacity was decreased according to the cycle number.

Example 8

LiNi _0.8 Co _0.1 Mn _0.1 O ₂ to which AlF ₃ was added and evaluated in the same manner as in Example 1, and then a battery was prepared using LiNi _0.8 Co _0.1 Mn _0.1 O ₂ to which AlF ₃ was added. . In order to evaluate the characteristics of the manufactured coin battery, an electrochemical analyzer (Toscat3000U, Japan, manufactured by Toyo) was used at 30 ° C., 3.0 to 4.5 V potential region, and 0.2 mA / cm 2. Charge and discharge experiments were carried out at a current density of 0.8 mA / cm 2. The capacity according to the cycle is shown in FIGS. 21 to 22. In the manufactured battery, the capacity was decreased according to the cycle number.

Comparative Example 1

The existing LiCoO ₂ positive electrode active material to which the fluorine compound was not added was characterized in the same manner as in Example 1. 4 is an XRD pattern of the positive electrode active material obtained in Example 1 and Comparative Example 1. FIG. Moreover, the FE-SEM photograph of the positive electrode active material obtained by the comparative example 1 is shown in FIG. The cycle curves of the half cell experimented in the voltage range of 3.0-4.5 kV and 30 degreeC constant current density 0.2 mA / cm <2> of the positive electrode active material of Example 1 and the comparative example 1 are shown in FIG. 8, and the positive electrode of Example 1 and the comparative example 1 is shown. The cycle curve of the half cell experimented in the voltage range of 3.0-4.5 kV, 30 degreeC constant current density 0.8 mA / cm <2> of an active material is shown in FIG. The cycle curve of the half cell experimented in the voltage range 3.0-4.5V and 30 degreeC constant current density 0.2mA / cm <2> of the positive electrode active material of Examples 1-4 and Comparative Example 1 of this invention is shown in FIG.

Comparative Example 2

LiNi without AlF _{3 0.5} Mn _0.5 O ₂ The positive electrode active material was characterized in the same manner as in Example 1. 11 is an XRD pattern of the positive electrode active material obtained in Example 5 and Comparative Example 2. FIG. In addition, the cycle curves of the half cell experimented in the voltage range of 2.8 to 4.5 kV at 30 ° C. constant current density of 0.2 mA / cm 2 of Example 5 and Comparative Example 2 are shown in FIG. 12, Example 5 and Comparative Example 2 The cycle curve of the half cell experimented in the voltage range of 2.8-4.5 kV and 30 degreeC constant current density of 0.8 mA / cm <2> of the positive electrode active material of is shown in FIG.

Comparative Example 3

The LiNi _1/3 Co _1/3 Mn _1/3 O ₂ positive electrode active material to which AlF ₃ was not added was characterized in the same manner as in Example 1. 14 is an XRD pattern of the positive electrode active material obtained in Example 6 and Comparative Example 3. FIG. In addition, the cycle curves of the half cell experimented in the voltage range of 2.8 to 4.6 kW and the constant current density of 0.2 mA / cm 2 at the positive electrode active materials of Example 6 and Comparative Example 3 are shown in FIG. 15, Example 6 and Comparative Example 3 The cycle curve of the half cell experimented in the voltage range of 2.8-4.6 kV, 30 degreeC constant current density of 0.8 mA / cm <2> of the positive electrode active material of is shown in FIG.

[Comparative Example 4]

The LiNi _0.4 Co _0.2 Mn _0.4 O ₂ positive electrode active material to which AlF ₃ was not added was characterized in the same manner as in Example 1. 17 is an XRD pattern of the positive electrode active material obtained in Example 7 and Comparative Example 4. FIG. In addition, the cycle curves of the half cell experimented in the voltage range of 2.8 to 4.6 kV at 30 ° C constant current density of 0.2 mA / cm 2 of the positive electrode active materials of Example 7 and Comparative Example 4 are shown in FIG. 18, Example 7 and Comparative Example 4 19 shows a cycle curve of a half cell tested at a voltage range of 2.8 to 4.6 kW and a constant current density of 0.8 mA / cm 2 at 30 ° C. of the cathode active material.

[Comparative Example 5]

The LiNi _0.8 Co _0.1 Mn _0.1 O ₂ positive electrode active material to which AlF ₃ was not added was characterized in the same manner as in Example 1. 20 is XRD patterns of the positive electrode active materials obtained in Example 8 and Comparative Example 5. FIG. In addition, the cycle curves of the half cell experimented in the voltage range of 3.0 to 4.5 kV at 30 ° C constant current density of 0.2 mA / cm 2 of the positive electrode active materials of Example 8 and Comparative Example 5 are shown in FIG. 21, Example 8 and Comparative Example 5 22 shows a cycle curve of the half cell tested at a voltage range of 3.0 to 4.5 kW and a constant current density of 0.8 mA / cm 2 at 30 ° C.

Therefore, according to the present invention, a fine powder fluorine compound is synthesized with a lithium secondary battery positive electrode active material additive and added to the positive electrode active material for lithium secondary battery to prepare a positive electrode active material for lithium secondary battery to which the fluorine compound is added to acid generated near the positive electrode active material. It is possible to provide a cathode active material having excellent charge / discharge characteristics, lifespan characteristics, high voltage, and high rate characteristics by reducing the influence on the cathode active material or reducing the capacity of the battery by reducing the reactivity between the cathode active material and the electrolyte.

Claims (7)

      In a lithium secondary battery positive electrode active material, Lithium secondary battery positive electrode active material characterized in that the complex salt is added to the fluorine compound in the positive electrode active material. The method of claim 1, wherein the fluorine compound is CsF, KF, LiF, NaF, RbF, TiF, AgF, AgF₂, BaF ₂ , CaF ₂ , CuF ₂ , CdF ₂ , FeF ₂ , HgF ₂ , Hg ₂ F ₂ , MnF ₂ , MgF ₂ , NiF ₂ , PbF ₂ , SnF ₂ , SrF ₂ , XeF ₂ , ZnF ₂ , AlF ₃ , BF ₃ , BiF ₃ , CeF ₃ , CrF ₃ , DyF ₃ , EuF ₃ , GaF ₃ , GdF ₃ , _{FeF 3, HoF 3, InF 3} , LaF 3, LuF 3, MnF 3, NdF 3, VOF 3, PrF 3, SbF 3, ScF 3, SmF 3, TbF 3, TiF 3, TmF 3, YF 3, YbF 3 _{, TIF 3, CeF 4, GeF} 4, HfF 4, SiF 4, SnF 4, TiF 4, VF 4, ZrF 4, NbF 5, SbF 5, TaF 5, BiF 5, MoF 6, ReF 6, SF 6 and WF Lithium secondary battery positive electrode active material, characterized in that any one or more selected from the group consisting of ₆ and all compounds containing fluorine. The cathode active material to which the fluorine compound is added is Li _{1 + a} [Co _1-x M _x ] O _2-b N _b having a hexagonal layered rock salt structure (0.01 ≦ a ≦ 0.2, 0.01 ≦ b≤0.2, 0.01≤x≤ 0.1, M = Mg, at least one metal selected from the group consisting of Al, Ni, Mn, Zn, Fe, Cr, Ga, Mo and W, N is F or S), hexagonal system Li _{1 + a} [Ni _1-x M _x ] O _2-b N _b having a layered rock salt structure (0.01 ≦ a ≦ 0.2, 0.01 ≦ _b ≦ 0.2, 0.01 ≦ x ≦ 0.5, M = Mg, Al, Co, At least one metal selected from the group consisting of Mn, Zn, Fe, Cr, Ga, Mo, W, N is F or S), Li _{1 + a} [Ni _1-xy Co _x Mn _y having a hexagonal layered rock salt structure _; ] O _2-b N _b (0.01≤a≤0.2, 0.01≤b≤0.1, 0.05≤x≤0.3, 0.1≤y≤0.35, 0.15≤x + y≤0.6, N is F or S), hexagonal layered Li [Li _a (Ni _x Co _1-2x Mn _x ) _1-a ] O _2-b N _b having a rock salt structure (0.01≤a≤0.2, 0.01≤x≤0.5, 0.01≤b≤0.1, N is F Or S), Li [Li _a (Ni _x Co _1-) having a hexagonal layered rock salt structure. _2x Mn _{xy / 2} M _y ) _1-a ] O _2-b N _b (M = Mg, Ca, Cu, Zn at least one metal selected from the group consisting of 0.01 ≦ a ≦ 0.2, 0.01 ≦ x ≦ 0.5, 0.01≤y≤0.1, 0.01≤b≤0.1, N is F or S), Li [Li _a (Ni _1/3 Co _{(1 / 3-2x)} Mn _{( 1/3 + x} ) with hexagonal layered rock salt structure ₎ M _x ) _1-a ] O _2-b N _b (M = Mg, Ca, Cu, Zn at least one metal selected from the group consisting of, 0.01≤a≤0.2, 0.01≤x≤0.5, 0.01≤y≤ 0.1, 0.01 ≦ bV0.1, N is F or S), Li [Li _a (Ni _x Co _1-2x-y Mn _x M _y ) _1-a ] O _2-b N _{b with} hexagonal layered rock salt structure (At least one metal selected from the group consisting of M = B, Al, Fe, Cr, 0.01 ≦ a ≦ 0.2, 0.01 ≦ x ≦ 0.5, 0.01 ≦ y ≦ 0.1, 0.01 ≦ b ≦ 0.1, and N is F or S) , Li [Li _a (Ni _x Co _1-2x-y Mn _{xz / 2} M _y N _z ) _1-a ] O _2-b N _b (M = B, Al, Fe, Cr with hexagonal layered rock salt structure) At least one metal selected from the group consisting of N = Mg or Ca, 0.01 ≦ a ≦ 0.2, 0.01 ≦ x ≦ 0.5, 0.01 ≦ y ≦ 0. 1, 0.01 ≦ b ≦ 0.1, N is F or S), at least one metal selected from the group consisting of LiM _x Fe _1-x PO ₄ (M = Co, Ni, Mn) having an olivine structure, 0 ≦ _x ≦ 1), spinel Li _{1 + a} [Mn _2-x M _x ] O _4-b N _b having a cubic structure (0.01 ≦ a ≦ 0.15, 0.01 ≦ _b ≦ 0.2, M = Co, Ni, Cr, Mg, Al, Zn, Mo, W 0.01≤x≤0.1, N is F or S) and spinel Li _{1 + a} [Ni _0.5 Mn _1.5-x M _x ] O _4-b N _b (0.01≤) with cubic structure a≤0.15, 0.01≤b≤0.2, 0.01≤x≤0.1, M = Co, Ni, Cr, Mg, Al, Zn, Mo, at least one metal selected from the group W, N is F or S) Lithium secondary battery positive electrode active material characterized in that. After adding a solution in which fluorine (F) was dissolved in a high-dispersion fine powder element precursor solution, and reacting at 50 ° C. to 150 ° C. for 1 to 48 hours to form a high-dispersity fine powder fluorine compound in the form of a complex salt, the formed After drying the fine powder fluorine compound at 110 ℃ for 6 to 24 hours, heat treatment at 150 ℃ to 900 ℃ for 1 to 20 hours in any one of oxidizing atmosphere, reducing atmosphere and vacuum state to prepare the fine powder fluorine compound, A method of manufacturing a cathode active material for a lithium secondary battery, characterized in that 0.05 to 10 parts by weight of the fine powder fluorine compound is added and uniformly mixed with respect to 100 parts by weight of a cathode active material for a lithium secondary battery. The method of claim 4, wherein the element precursor solution is used in the concentration of 0.1 to 3M, the solution in which fluorine (F) is dissolved using a 0.1 to 18M concentration of the complex salt by reacting for 1 to 48 hours at 50 ℃ to 150 ℃ A method for producing a cathode active material for a lithium secondary battery, characterized in that to form a highly dispersed fine powder fluorine compound. The method of claim 4 or 5, wherein the element precursor is Cs, K, Li, Na, Rb, Ti, Ag (I), Ag (II), Ba, Ca, Cu, Cd, Fe, Hg (II) , Hg (I), Mn (II), Mg, Ni, Pb, Sn, Sr, Xe, Zn, Al, B, Bi (III), Ce (III), Cr, Dy, Eu, Ga, Gd, Fe , Ho, In, La, Lu, Mn (III), Nd, VO, Pr, Sb (III), Sc, Sm, Tb, Ti (III), Tm, Y, Yb, TI, Ce (IV), Ge Alkoxide salts of at least one element selected from the group consisting of Hf, Si, Sn, Ti (IV), V, Zr, Nb, Sb (V), Ta, Bi (V), Mo, Re, S and W , Sulfate, nitrate, acetate, chloride, phosphate any one compound, the method for producing a cathode active material for a lithium secondary battery. The solution of claim 4, wherein the solution in which fluorine (F) is dissolved to precipitate the element precursor in the complex salt form is used to precipitate elemental precursors such as NH ₄ F, HF, and A (Anhydrous) HF in the complex salt form. Method for producing a cathode active material for a lithium secondary battery, characterized in that the solution of at least one or more compounds selected from the group of compounds that can provide.

Images