KR20130077805A - Method for manufacturing positive active material for lithium secondary battery and positive active material for lithium secondary battery - Google Patents

Abstract

PURPOSE: A manufacturing method of a cathode active material is provided to be able to provide a cathode active material having an improved high index, long life property and high capacity. CONSTITUTION: A manufacturing method of a cathode active material comprises a step of preparing a coating solution by mixing a first solvent, a first Al supply material soluble in the first solvent, and a second Al supply material insoluble in the first solvent; a step of injecting lithium complex oxides to the coating solution and stirring so that the first Al supply material and the second Al supply material are coated on the lithium complex oxides; and a step of plasticizing the lithium complex oxides coated with the first Al supply material and the second Al supply material.

Description

Manufacturing method and positive electrode active material for positive electrode active material for lithium secondary battery TECHNICAL FIELD

It relates to a method for producing a cathode active material for a lithium secondary battery and a cathode active material.

Recently, with regard to the tendency to miniaturize and lighten portable electronic devices, there is an increasing need for high performance and large capacity of batteries used as power sources for these devices.

Cells generate electricity by using materials that can electrochemically react to the positive and negative electrodes. A typical example of such a battery is a lithium secondary battery that generates electrical 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 prepared 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.

A lithium composite metal compound is used as a cathode active material of a lithium secondary battery, and composite metal oxides such as LiCoO ₂ , LiMn ₂ O ₄ , LiNiO ₂ , and LiMnO ₂ have been 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 have low environmental pollution and are attractive. Although it has a disadvantage, the capacity is small.

LiCoO ₂ has a good electrical conductivity and a high battery voltage of about 3.7V, and also has excellent cycle life characteristics, stability, and discharge capacity, and thus, is a representative cathode active material commercially available and commercially available. However, since LiCoO ₂ is expensive, it takes up more than 30% of the battery price, and thus, price competitiveness is inferior.

In addition, LiNiO ₂ exhibits the highest discharge capacity of battery characteristics among the cathode active materials mentioned above, but has a disadvantage in that it is difficult to synthesize. In addition, the high oxidation state of nickel causes a decrease in battery and electrode life, and there is a problem of severe self discharge and inferior reversibility. In addition, it is difficult to commercialize the stability is not perfect.

LiNi _{0 .8} is a partial substitution of Co for LiNiO ₂ Co _{0 .2} O ₂ cathode material and to form a well layered structure required as the positive electrode material by the Co doped, where LiNi _0.8 Co _0.2 O ₂ for the structural stability to kkoehagi doping a part of Al in the positive electrode material _{LiNi 0 .8 Co 0 .15 Al 0} .05 O 2 ( hereinafter NCA) material that has been applied gradually expanded as the high-capacity materials.

Al element is widely used as a doping material to improve the structural stability of the positive electrode material, and is also widely used as an oxide coating material mainly for the purpose of improving the high rate characteristics and battery life. (KR 2002-0029218)

According to JP 1998-097857, a method for producing Al-containing nickel hydroxide is disclosed, but when Al is co-precipitated on a precursor, particle growth is not good and a high density precursor is difficult to obtain.

JP 2012-009458 discloses a technique for introducing Al by mixing and firing a lithium compound, a nickel compound, aluminum or an aluminum compound, but has difficulty in uniformly doping Al into an active material or controlling a desired doping thickness. have. In addition, JP 2010-24083 discloses a nickel cobalt composite hydroxide coated with aluminum hydroxide, but Al is diffused into the active material under baking conditions (750 ° C. or more) to have a sufficient crystal structure as a cathode material by mixing with a lithium compound. It has the disadvantage that doping thickness control is difficult.

Stirring and calcining the surface of the lithium composite oxide capable of intercalating / deintercalating lithium ions so as to coat a first Al feed material soluble in a solvent and a second Al feed material insoluble in a solvent Through the aluminum doped to the active material surface portion and remains in the form of a coating to provide a positive electrode active material having a higher capacity and improved high rate and long life characteristics than the conventional Al-introduced positive electrode material.

In one embodiment of the present invention, preparing a coating solution by mixing a first solvent, a first Al feed material soluble in the first solvent and a second Al feed material insoluble in the first solvent; Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring to coat the second Al feed material; And calcining a lithium composite oxide capable of intercalating / deintercalating lithium ions coated with the first Al supply material and the second Al supply material on the surface thereof. It provides a method for producing.

Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring the second Al feed material to be coated, wherein the second Al feed material is coated in an island form on a surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions. The first Al feed material may be coated on a lithium composite oxide surface capable of intercalating / deintercalating the lithium ions in a film form.

Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring the second Al feed material to be coated; swelling a lithium composite oxide capable of intercalating / deintercalating the lithium ions into a second solvent; And adding a lithium composite oxide capable of intercalating / deintercalating the swelled lithium ions into the coating solution to the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions. And stirring the 1 Al feed material and the second Al feed material to be coated.

Preparing a coating solution by mixing the first solvent, a first Al feed material soluble in the first solvent, and a second Al feed material insoluble in the first solvent, wherein the first solvent is soluble in the first solvent. Dissolving 1 Al feed material in said first solvent; And preparing a coating solution by mixing a second Al feed material which is insoluble in the first solvent in a solvent in which the first Al feed material is dissolved.

Preparing a coating solution by mixing the first solvent, a first Al feed material soluble in the first solvent, and a second Al feed material insoluble in the first solvent, wherein the first solvent is soluble in the first solvent. Dissolving 1 Al feed material in said first solvent; And preparing a coating solution by mixing a second Al supply material insoluble in the first solvent and a lithium supply material in a solvent in which the first Al supply material is dissolved.

The lithium feed material may be soluble in the first solvent.

The first solvent and the second solvent may be the same.

The first Al feed material soluble in the first solvent may be Al-alkoxide, Al-acetate, Al-nitrate, Al-sulfate, or a combination thereof.

The second Al feed material insoluble in the first solvent may be Al ₂ O ₃ , Al (OH) ₃ , or a combination thereof, but is not limited thereto.

The lithium supply material may be any one of nitrate, carbonate, acetate, oxalate, oxide, hydroxide, and sulfate including lithium. May be selected or a combination thereof.

The ratio of the second Al feed material / first Al feed material may be 1.5 to 4 based on the Al element.

Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring to coat the second Al feed material; Thereafter, the method may further include evaporating the first solvent included in the coating solution.

The lithium composite oxide capable of intercalating / deintercalating the lithium ions may be nickel-cobalt oxide or nickel-manganese oxide.

The lithium ion intercalation / de-intercalation of lithium composite oxide capable of migration _{is, Li a A 1 - b X} b D 2 (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5); _{Li a A 1 - b X b} O 2 - c T c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); LiE _{1 - b} X _b O _{2 - c} D _c (0? B? 0.5, 0? C? 0.05); LiE _2-b X _b 0 _4-c T _c (0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.05); Li _a Ni _{1 -b- c} Co _b X _c D _? (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <?? 2); Li _a Ni _{1 -b- c} Co _b X _c O _{2 -α} T _α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2); Li _a Ni _{1 -b- c} Co _b X _c O _{2 - ?} T ₂ (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <? <2); Li _a Ni _{1 -b- c} Mn _b X _c D _? (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <?? 2); Li _a Ni _{1 -b- c} Mn _b X _c O _{2- α} T _α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2); Li _a Ni _{1 -b- c} Mn _b X _c O _{2 - ?} T ₂ (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <? <2); Li _a Ni _b E _c G _d O ₂ (0.90? A? 1.8, 0? B? 0.9, 0? C? 0.5, 0.001? D? 0.1); Li _a Ni _b Co _c Mn _d G _e O ₂ (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0.001 ≤ e ≤ 0.1); Li _a NiG _b O ₂ (0.90? A? 1.8, 0.001? B? 0.1); Li _a CoG _b O ₂ (0.90? A? 1.8, 0.001? B? 0.1); Li _a MnG ′ _b O ₂ (0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1); Li _a Mn ₂ G _b O ₄ (0.90? A? 1.8, 0.001? B? 0.1); Li _a MnG ′ _b PO ₄ (0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1); LiNiVO _4; And Li _(3-f) J ₂ (PO ₄ ) ₃ (0 ≦ f ≦ 2).

In the above formula, A is selected from the group consisting of Ni, Co, Mn, and combinations thereof; X is selected from the group consisting of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements and combinations thereof; D is selected from the group consisting of O, F, S, P, and combinations thereof; E is selected from the group consisting of Co, Mn, Ni, and combinations thereof; T is selected from the group consisting of F, S, P, and combinations thereof; G is selected from the group consisting of Ni, Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and combinations thereof; G` is selected from the group consisting of Ni, Al, Cr, Fe, Mg, La, Ce, Sr, V and combinations thereof; Q is selected from the group consisting of Ti, Mo, Mn, Ni, and combinations thereof; Z is selected from the group consisting of Cr, V, Fe, Sc, Y, Ni, and combinations thereof; J is selected from the group consisting of V, Cr, Mn, Co, Ni, Cu, and combinations thereof.

Preparing a coating solution by mixing the first solvent, a first Al supply material soluble in the first solvent, and a second Al supply material insoluble in the first solvent; the first solvent, the first solvent Preparing a coating solution by mixing a first Al supply material soluble in a solvent, a second Al supply material insoluble in the first solvent, and a lithium supply material.

Calcining a lithium composite oxide capable of intercalating / deintercalating lithium ions coated with the first Al supply material and the second Al supply material on the surface; The first Al feed material coated in a film form diffuses into the lithium composite oxide to form an Al doping layer, and the second feed material coated in an island form on the surface of the lithium composite oxide forms a film on the surface of the lithium composite oxide. May be coated to form an Al coating layer.

In another embodiment of the present invention, lithium composite oxide core particles capable of intercalating / deintercalating lithium ions; An Al doped layer diffused inward from the surface portion of the core particles; And it provides a cathode active material for a lithium secondary battery comprising an Al coating layer formed on the surface of the core particles.

The lattice constant of the X-ray diffraction image (XRD) phase of the positive electrode active material may have a value of 2.864 to 2.868 Å.

The Al coating layer may be a coating layer containing Li-Al.

The lithium composite oxide core particles capable of intercalating / deintercalating the lithium ions may be represented by the following Chemical Formula 1.

[Formula 1]

LiNi _x Co _y M _z O _{2 - t} S _t

(In Formula 1, 0.5 <x <0.9, 0 <y <0.25, 0 ≦ z <0.1, 0 ≦ t <0.1, M is Al, B, Mg, Ti, Mn or Zr, and S is Cl, F or S.)

The cathode active material may be prepared by the manufacturing method according to the embodiment of the present invention described above.

It is to provide a cathode active material having high capacity and improved high rate and long life characteristics.

1 is a schematic view of a lithium secondary battery.

Hereinafter, embodiments of the present invention will be described in detail. However, it should be understood that the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

In one embodiment of the present invention, lithium composite oxide core particles capable of intercalating / deintercalating lithium ions; An Al doped layer diffused inward from the surface portion of the core particles; And it provides a cathode active material for a lithium secondary battery comprising an Al coating layer formed on the surface of the core particles.

The cathode active material may be appropriately doped and / or coated with Al to improve the life characteristics of the battery using the same.

The Al doped layer may have a thickness of 0.5 to 3㎛.

In addition, the Al coating layer may have a thickness of 10 to 100nm.

More specifically, the cathode active material may have a lattice constant of a value of 2.864 to 2.868 Å due to an Al doped layer diffused from the surface portion of the core particle into the X-ray diffraction image (XRD). When satisfying this range, there can be a long life effect without reducing the initial dose.

The Al coating layer may be a Li-Al composite compound based on the remaining lithium on the surface of the active material or a separately added Li source.

The lithium composite oxide core particles capable of intercalating / deintercalating the lithium ions may be represented by the following Chemical Formula 1, but are not limited thereto.

[Formula 1]

LiNi _x Co _y M _z O _{2 - t} S _t

(In Formula 1, 0.5 <x <0.9, 0 <y <0.25, 0 ≦ z <0.1, 0 ≦ t <0.1, M is Al, B, Mg, Ti, Mn or Zr, and S is Cl, F or S.)

More specifically, the lithium composite oxide core particles capable of intercalating / deintercalating the lithium ions may be represented by the following Chemical Formula 1-1, but are not limited thereto.

[Formula 1-1]

LiNi _x Co _y M _z O _{2 - t} S _t

(In Formula 1-1, 0.5 <x <0.9, 0 <y <0.20, 0 ≦ z <0.08, 0 ≦ t <0.1, M is Al, B, Mg, Ti, Mn or Zr, and S is Cl, F or S.)

Hereinafter, a method of manufacturing the cathode active material will be described in more detail.

In one embodiment of the present invention, preparing a coating solution by mixing a first solvent, a first Al feed material soluble in the first solvent and a second Al feed material insoluble in the first solvent; Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring to coat the second Al feed material; And calcining a lithium composite oxide capable of intercalating / deintercalating lithium ions coated with the first Al supply material and the second Al supply material on the surface thereof. It provides a method for producing.

The positive electrode active material may be appropriately doped and coated with an Al component by simultaneously using a first Al supply material soluble in the first solvent and a second Al supply material insoluble in the first solvent. This may improve the battery life characteristics.

More specifically, a lithium composite oxide capable of intercalating / deintercalating lithium ions is introduced into the coating solution to the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions. Stirring to coat the 1 Al feed material and the second Al feed material; wherein the second Al feed material has an island form on a lithium composite oxide surface capable of intercalating / deintercalating the lithium ions. The first Al feed material may be coated on a lithium composite oxide surface capable of intercalating / deintercalating the lithium ions in a film form.

Calcining a lithium composite oxide capable of intercalating / deintercalating lithium ions coated with the first Al supply material and the second Al supply material on the surface; The first Al feed material coated in a film form diffuses into the lithium composite oxide to form an Al doping layer, and the second feed material coated in an island form on the surface of the lithium composite oxide forms a film on the surface of the lithium composite oxide. May be coated to form an Al coating layer.

Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring the second Al feed material to be coated; swelling a lithium composite oxide capable of intercalating / deintercalating the lithium ions into a second solvent; And adding a lithium composite oxide capable of intercalating / deintercalating the swelled lithium ions into the coating solution to the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions. And stirring the 1 Al feed material and the second Al feed material to be coated.

By this step, the first Al supply material and the second Al supply material may react more effectively with the lithium composite oxide capable of intercalating / deintercalating the lithium ions.

Preparing a coating solution by mixing the first solvent, a first Al feed material soluble in the first solvent, and a second Al feed material insoluble in the first solvent, wherein the first solvent is soluble in the first solvent. Dissolving 1 Al feed material in said first solvent; And preparing a coating solution by mixing a second Al feed material which is insoluble in the first solvent in a solvent in which the first Al feed material is dissolved. However, if the materials can be mixed effectively, a mixing method There is no limit.

Preparing a coating solution by mixing the first solvent, a first Al supply material soluble in the first solvent, and a second Al supply material insoluble in the first solvent; the first solvent, the first solvent Preparing a coating solution by mixing a first Al supply material soluble in a solvent, a second Al supply material insoluble in the first solvent, and a lithium supply material.

More specifically, preparing a coating solution by mixing the first solvent, the first Al feed material soluble in the first solvent and the second Al feed material insoluble in the first solvent; Dissolving a first Al feed material soluble in the first solvent; And preparing a coating solution by mixing a second Al supply material insoluble in the first solvent and a lithium supply material in a solvent in which the first Al supply material is dissolved.

As such, when the lithium supply material is additionally included, lithium which may be lost in the subsequent firing step may be replenished, and doping of Al may be promoted by lithium, thereby improving the lifespan characteristics of the battery.

More specifically, the lithium feed material may be soluble in the first solvent.

The lithium supply material may be any one of nitrate, carbonate, acetate, oxalate, oxide, hydroxide, and sulfate including lithium. May be selected or a combination thereof, but is not limited thereto.

The first solvent is ethyl alcohol, methyl alcohol, normal propyl alcohol, n-propyl alcohol, i-propyl alcohol, normal butyl alcohol, sec It may be an alcohol solvent of butyl alcohol (sec-butyl alcohol) and tert-butyl alcohol (tert-butyl alcohol).

The second solvent may be an alcohol solvent, water, acetone, or the like.

The first solvent and the second solvent may be the same.

The first Al feed material soluble in the first solvent may be, but is not limited to, Al-alkoxide, Al-acetate, Al-nitrate, Al-sulfate, or a combination thereof.

The second Al feed material insoluble in the first solvent may be Al ₂ O ₃ , Al (OH) ₃ , or a combination thereof, but is not limited thereto.

The ratio of the first Al feed material and the second Al feed material (based on the Al element, the second Al feed material / first Al feed material) may be 1.5 to 4. In this case, doping and coating can take place effectively. When the ratio is less than 1.5, the amount of the soluble Al feed material for doping and coating is relatively increased, causing ignition due to the catalytic properties of the nano Al compound during firing. In addition, if the ratio exceeds 4, the amount of insoluble Al feedstock is increased so that doping may not be sufficient and an excess of Al compound remains on the surface.

Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring to coat the second Al feed material; Thereafter, the method may further include evaporating the first solvent included in the coating solution. By this process, the subsequent firing process may be more effective.

The lithium composite oxide capable of intercalating / deintercalating the lithium ions may be nickel-cobalt-based oxide or nickel-cobalt-manganese oxide and nickel-manganese oxide.

Or a lithium composite oxide capable of intercalating / deintercalating the lithium ions,

Li _a A _{1 - b} X _b D ₂ (0.90? A? 1.8, 0? B? 0.5); _{Li a A 1 - b X b} O 2 - c T c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); LiE _{1 - b} X _b O _{2 - c} D _c (0? B? 0.5, 0? C? 0.05); _{LiE 2 - b X b O 4} - c T c (0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li _a Ni _{1 -b- c} Co _b X _c D _? (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <?? 2); Li _a Ni _{1 -b- c} Co _b X _c O _{2 -α} T _α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2); Li _a Ni _{1 -b- c} Co _b X _c O _{2 - ?} T ₂ (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <? <2); Li _a Ni _{1 -b- c} Mn _b X _c D _? (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <?? 2); Li _a Ni _{1 -b- c} Mn _b X _c O _{2- α} T _α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2); Li _a Ni _{1 -bc} Mn _b X _c O _2-α T ₂ (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2); Li _a Ni _b E _c G _d O ₂ (0.90? A? 1.8, 0? B? 0.9, 0? C? 0.5, 0.001? D? 0.1); Li _a Ni _b Co _c Mn _d G _e O ₂ (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0.001 ≤ e ≤ 0.1); Li _a NiG _b O ₂ (0.90? A? 1.8, 0.001? B? 0.1); Li _a CoG _b O ₂ (0.90? A? 1.8, 0.001? B? 0.1); Li _a MnG ′ _b O ₂ (0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1); Li _a Mn ₂ G _b O ₄ (0.90? A? 1.8, 0.001? B? 0.1); Li _a MnG ′ _b PO ₄ (0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1); LiNiVO _4; And Li _(3-f) J ₂ (PO ₄ ) ₃ (0 ≦ f ≦ 2).

In the above formula, A is selected from the group consisting of Ni, Co, Mn, and combinations thereof; X is selected from the group consisting of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements and combinations thereof; D is selected from the group consisting of O, F, S, P, and combinations thereof; E is selected from the group consisting of Co, Mn, Ni, and combinations thereof; T is selected from the group consisting of F, S, P, and combinations thereof; G is selected from the group consisting of Ni, Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and combinations thereof; G` is selected from the group consisting of Ni, Al, Cr, Fe, Mg, La, Ce, Sr, V and combinations thereof; Q is selected from the group consisting of Ti, Mo, Mn, Ni, and combinations thereof; Z is selected from the group consisting of Cr, V, Fe, Sc, Y, Ni, and combinations thereof; J is selected from the group consisting of V, Cr, Mn, Co, Ni, Cu, and combinations thereof.

In another embodiment of the present invention, a lithium secondary battery including a positive electrode, a negative electrode and an electrolyte, the positive electrode includes a current collector and a positive electrode active material layer formed on the current collector, the positive electrode active material layer, It provides a lithium secondary battery comprising one cathode active material.

Descriptions related to the cathode active material are omitted because they are the same as the above-described embodiments of the present invention.

The positive electrode active material layer may include a binder and a conductive material.

The binder serves to adhere the positive electrode active material particles to each other and to adhere the positive electrode active material to the current collector. Typical examples thereof include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl Polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-acrylonitrile, styrene-butadiene rubber, Butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, and the like, but not limited thereto.

The conductive material is used for imparting conductivity to the electrode. Any conductive material can be used without causing any chemical change in the battery. Examples of the conductive material include natural graphite, artificial graphite, carbon black, acetylene black, Carbon-based materials such as black and carbon fiber; Metal powders such as copper, nickel, aluminum, and silver, or metal-based materials such as metal fibers; Conductive polymers such as polyphenylene derivatives; Or a mixture thereof may be used.

The negative electrode includes a current collector and a negative active material layer formed on the current collector, and the negative active material layer includes a negative active material.

The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, a lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

As a material capable of reversibly intercalating / deintercalating the lithium ions, any carbon-based negative electrode active material generally used in a lithium ion secondary battery may be used, and representative examples thereof include crystalline carbon. , Amorphous carbon or these can be used together. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite in the form of amorphous, plate-like, flake, spherical or fibrous type. Examples of the amorphous carbon include soft carbon (soft carbon) Or hard carbon, mesophase pitch carbide, fired coke, and the like.

As the lithium metal alloy, a lithium-metal alloy may be selected from the group consisting of lithium, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, An alloy of a selected metal may be used.

As the material capable of doping and dedoping lithium, Si, SiO _x (0 <x <2), Si-Y alloy (Y is an alkali metal, an alkali earth metal, a Group 13 element, a Group 14 element, Rare earth elements and combinations thereof, but not Si), Sn, SnO ₂ , Sn-Y (wherein Y is at least one element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, Element and an element selected from the group consisting of combinations thereof, and not Sn), and at least one of them may be mixed with SiO ₂ . The element Y may be at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Ge, P, As, Sb, Se, Te, Po, and combinations thereof.

Examples of the transition metal oxide include vanadium oxide, lithium vanadium oxide, and the like.

The negative electrode active material layer also includes a binder, and may optionally further include a conductive material.

The binder serves to adhere the anode active material particles to each other and to adhere the anode active material to the current collector. Typical examples thereof include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, Such as polyvinyl chloride, polyvinyl fluoride, polymers comprising ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, Styrene-butadiene rubber, epoxy resin, nylon, and the like may be used, but the present invention is not limited thereto.

The conductive material is used for imparting conductivity to the electrode. Any conductive material can be used without causing any chemical change in the battery. Examples of the conductive material include natural graphite, artificial graphite, carbon black, acetylene black, Carbon-based materials such as black and carbon fiber; Metal powders such as copper, nickel, aluminum, and silver, or metal-based materials such as metal fibers; Conductive polymers such as polyphenylene derivatives; Or a mixture thereof may be used.

The collector may be selected from the group consisting of a copper foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foil, a polymer substrate coated with a conductive metal, and a combination thereof.

As the current collector, Al may be used, but the present invention is not limited thereto.

The negative electrode and the positive electrode are prepared by mixing an active material, a conductive material and a binder in a solvent to prepare an active material composition, and applying the composition to a current collector. The method of manufacturing the electrode is well known in the art, and therefore, a detailed description thereof will be omitted herein. N-methylpyrrolidone may be used as the solvent, but is not limited thereto.

The electrolyte contains a non-aqueous organic solvent and a lithium salt.

The non-aqueous organic solvent serves as a medium through which ions involved in the electrochemical reaction of the battery can move.

As the non-aqueous organic solvent, a carbonate-based, ester-based, ether-based, ketone-based, alcohol-based or aprotic solvent may be used. Examples of the carbonate solvent include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl ethyl carbonate (MEC) EC), propylene carbonate (PC), and butylene carbonate (BC) may be used. As the ester solvent, methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate , gamma -butyrolactone, decanolide, valerolactone, mevalonolactone, caprolactone, and the like can be used. Examples of the ether solvent include dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, and tetrahydrofuran. As the ketone solvent, cyclohexanone may be used have. As the alcoholic solvent, ethyl alcohol, isopropyl alcohol and the like can be used. As the aprotic solvent, R-CN (R is a linear, branched or cyclic hydrocarbon group having 2 to 20 carbon atoms, , A double bond aromatic ring or an ether bond), and dioxolanes such as 1,3-dioxolane, sulfolanes, and the like can be used.

The non-aqueous organic solvent may be used alone or in admixture of one or more. If the non-aqueous organic solvent is used in combination, the mixing ratio may be appropriately adjusted according to the desired cell performance. .

In the case of the carbonate-based solvent, it is preferable to use a mixture of a cyclic carbonate and a chain carbonate. In this case, when the cyclic carbonate and the chain carbonate are mixed in a volume ratio of 1: 1 to 1: 9, the performance of the electrolytic solution may be excellent.

The non-aqueous organic solvent of the present invention may further comprise an aromatic hydrocarbon-based organic solvent in the carbonate-based solvent. In this case, the carbonate solvent and the aromatic hydrocarbon organic solvent may be mixed in a volume ratio of 1: 1 to 30: 1.

As the aromatic hydrocarbon organic solvent, an aromatic hydrocarbon compound of Formula 2 may be used.

[Formula 2]

(In Chemical Formula 2, R ₁ to R ₆ are each independently hydrogen, halogen, C1 to C10 alkyl group, haloalkyl group, or a combination thereof.)

The aromatic hydrocarbon-based organic solvent is selected from the group consisting of benzene, fluorobenzene, 1,2-difluorobenzene, 1,3-difluorobenzene, 1,4-difluorobenzene, 1,2,3- , 1,2,4-trifluorobenzene, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,3-trichlorobenzene, 4-trichlorobenzene, iodobenzene, 1,2-diiodobenzene, 1,3-diiodobenzene, 1,4-diiodobenzene, 1,2,3-triiodobenzene, 1,2,4 - triiodobenzene, toluene, fluorotoluene, 1,2-difluorotoluene, 1,3-difluorotoluene, 1,4-difluorotoluene, 1,2,3-trifluorotoluene, 1,2,4-trifluorotoluene, chlorotoluene, 1,2-dichlorotoluene, 1,3-dichlorotoluene, 1,4-dichlorotoluene, 1,2,3-trichlorotoluene, 1,2,4 - trichlorotoluene, iodotoluene, 1,2-diiodotoluene, 1,3-diiodotoluene, 1,4-diiodotol Yen, it is 1,2,3-tree-iodo toluene, 1,2,4-iodo toluene, xylene, and selected from the group consisting of.

The non-aqueous electrolyte may further include vinylene carbonate or an ethylene carbonate-based compound of Formula 3 to improve battery life.

(3)

In Formula 3, R ₇ and R ₈ are each independently hydrogen, a halogen group, a cyano group (CN), a nitro group (NO ₂ ), or a C1 to C5 fluoroalkyl group, and at least one of R ₇ and R ₈ Is a halogen group, cyano group (CN), nitro group (NO ₂ ) or C1 to C5 fluoroalkyl group.)

Representative examples of the ethylene carbonate-based compound include diethylene carbonate, diethylene carbonate, dibromoethylene carbonate, nitroethylene carbonate, cyanoethylene carbonate, fluoroethylene carbonate, and the like, such as difluoroethylene carbonate, chloroethylene carbonate, dichloroethylene carbonate, . When such a life improving additive is further used, its amount can be appropriately adjusted.

The lithium salt is a substance that dissolves in an organic solvent, acts as a source of lithium ions in the battery to enable operation of the basic lithium secondary battery, and promotes movement of lithium ions between the positive electrode and the negative electrode. Representative examples of such lithium salts are LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ , LiC ₄ F ₉ SO ₃ , LiClO ₄ , LiAlO ₂ , LiAlCl ₄ , LiN (C _x F _{2x + 1} SO ₂ ) (C _y F _{2y +1} SO ₂ ), where x and y are natural water, LiCl, LiI and LiB (C ₂ O ₄ ) ₂ (lithium bis (oxalato) borate (LiBOB) Including one or more of the supporting electrolytic salt, the concentration of the lithium salt is preferably used within the range of 0.1 to 2.0 M. When the concentration of the lithium salt is included in the above range, the electrolyte has an appropriate conductivity and viscosity It can exhibit excellent electrolyte performance, and lithium ions can move effectively.

Depending on the type of the lithium secondary battery, a separator may exist between the positive electrode and the negative electrode. The separator may be a polyethylene / polypropylene double layer separator, a polyethylene / polypropylene / polyethylene triple layer separator, a polypropylene / polyethylene / poly It is needless to say that a mixed multilayer film such as a propylene three-layer separator and the like can be used.

The lithium secondary battery may be classified into a lithium ion battery, a lithium ion polymer battery, and a lithium polymer battery according to the type of separator and electrolyte used, and may be classified into a cylindrical shape, a square shape, a coin type, a pouch type, and the like. Depending on the size, it can be divided into bulk type and thin film type. The structure and the manufacturing method of these cells are well known in the art, and detailed description thereof will be omitted.

1 schematically shows a typical structure of a lithium secondary battery of the present invention. As shown in FIG. 3, the lithium secondary battery 1 includes a positive electrode 3, a negative electrode 2, and an electrolyte solution impregnated in a separator 4 existing between the positive electrode 3 and the negative electrode 2. The container 5 and the sealing member 6 which encloses the said battery container 5 are included.

Hereinafter, examples and comparative examples of the present invention will be described. The following embodiments are only examples of the present invention, and the present invention is not limited to the following embodiments.

Example

Example  1: Preparation of Positive Electrode Active Material

After dispersing Al-Isopropoxide finely in Al-Isopropoxide in isopropyl alcohol through high-speed stirring, it was heated to a temperature of 40 ° C. or higher to prepare a 6 wt% coating solution in which Al-Isopropoxide was completely dissolved in isopropyl alcohol. It was. To 43 g of the prepared coating solution, 5 g of Li acetate and 2.5 g of insoluble Al (OH) ₃ were added thereto to prepare a coating slurry by high-speed stirring.

A lithium compound oxide core particles was swollen with isopropyl alcohol for _{LiNi 0 .84 Co 0 .16 O 2} 100g. The isophthalic the _{LiNi 0 .84 LiNi 0 .84 Co 0} .16 O 2 in the coating solution and then added to the slurry coating liquid on Co _{0 .16} O ₂ swell in isopropyl alcohol and stirred for about one hour in order to thoroughly. Subsequently, the Al compound was coated on a LiNi _0.84 Co _0.16 O ₂ Core by evaporating the alcohol while stirring at 60 ° C. under vacuum. At this time, the ratio of insoluble Al feed material / soluble Al feed material was 2.52 based on Al element.

Heat treatment was performed at 700 ° C. for 8 hours while the alcohol was removed, and the heat-treated active material was dispersed through ultrasonic shift (Shift) to prepare a cathode active material. Measurement of the C content of the prepared active material and battery performance using the same are shown in Table 1 below.

Example  2: Preparation of Positive Electrode Active Material

Insoluble in the coating liquid prepared 60g relative to the element Al for LiNi _0.84 Co _0.16 O ₂ 100g of Li acetate 5g and insoluble Al (OH) ₃ as the respective 2.1g lithium composite oxide core particles through a high speed stirring to prepare a coating slurry is poured A lithium composite oxide capable of intercalating / deintercalating lithium ions was prepared in the same manner as in Example 1 except that the ratio of the Al feed material / soluble Al feed material was coated to be 1.5.

Example  3: Preparation of Positive Electrode Active Material

To 30 g of the prepared coating solution, 5 g of Li acetate and 2.8 g of insoluble Al (OH) ₃ were added thereto to prepare a coating slurry by stirring at high speed. In addition, 100 g of LiNi _0.84 Co _0.16 O ₂ as a lithium composite oxide core particle was insoluble based on Al element. A lithium composite oxide capable of intercalating / deintercalating lithium ions was prepared in the same manner as in Example 1 except that the ratio of the Al feed material / soluble Al feed material was coated to 4.

Example  4: Preparation of Positive Electrode Active Material

A lithium composite oxide capable of intercalating / deintercalating lithium ions was prepared in the same manner as in Example 2 except that Li actetate was not added.

Example  5: Preparation of Positive Electrode Active Material

A lithium compound oxide core particles _{LiNi 0 .838 Co 0 .16 Zr 0} .002 O and ₂ except for using 100g of Example 1 and a lithium ion in the same way inter knife migration / de intercalation lithium compound capable of Oxides were prepared.

Example  6: Preparation of positive electrode active material

A lithium compound oxide core particles _{LiNi 0 .838 Co 0 .16 Ti 0} .002 O and ₂ except for using 100g of Example 1 and a lithium ion in the same way inter knife migration / de intercalation lithium compound capable of Oxides were prepared

Example  7: Preparation of positive electrode active material

A lithium compound oxide core particles _{LiNi 0 .838 Co 0 .16 Mg 0} .002 O and ₂ except for using 100g of Example 1 and a lithium ion in the same way inter knife migration / de intercalation lithium compound capable of Oxides were prepared

Example  8: Preparation of Positive Electrode Active Material

A lithium compound oxide core particles, except for using _{LiNi 0 .70 Co 0 .15 Mn 0} .15 O 2 100g in Example 1 and the intercalation / lithium ions in the same manner di lithium intercalation compound capable of Oxides were prepared

Example  9: Preparation of Positive Electrode Active Material

A lithium compound oxide core particles, except for using _{LiNi 0 .60 Co 0 .20 Mn 0} .20 O 2 100g in Example 1 and the intercalation / lithium ions in the same manner di lithium intercalation compound capable of Oxides were prepared

Comparative example  1: Preparation of Positive Electrode Active Material

LiOH (manufacturer: SQM) and the Ni _{0 .84 Co 0 .16 (OH)} 2 1: 1.08: in a weight ratio of (a precursor Li), but mixed using a mixer at a reaction time of 6 hours in air to an elevated temperature, maintaining section A sintered body was produced at 750 ° C. for 7 hours and a total firing time of 20 hours.

The resulting fired body was slowly cooled and pulverized to prepare a positive electrode active material powder of the lithium metal composite oxide of the present invention. The obtained active material is shown in Table 1 by measuring the C content and preparing a battery using the same, evaluating battery performance.

Comparative example  2: Preparation of Positive Electrode Active Material

And Li acetate 5g In the prepared coating solution 152g to prepare a coating solution through a high speed stirring as a lithium compound oxide core particles as in Example 1 except that the coating only soluble Al feed material for the _{LiNi 0 .84 Co 0 .16 O 2} 100g In the same manner, a lithium composite oxide capable of intercalating / deintercalating lithium ions was prepared.

Comparative example  3: Preparation of Positive Electrode Active Material

Into the prepared coating solution 76g of Li acetate 5g and 1.8g of insoluble Al (OH) ₃ , respectively, was added at a high speed to prepare a coating slurry. The lithium composite oxide core particles were insoluble based on Al element for 100g of LiNi _0.84 Co _0.16 O _2. A lithium composite oxide capable of intercalating / deintercalating lithium ions was prepared in the same manner as in Example 1 except that the ratio of the Al feed material / soluble Al feed material was coated to 1.0.

Comparative example  4: Preparation of Positive Electrode Active Material

To 5 g of the prepared coating solution, 5 g of Li acetate and ₃ g of insoluble Al (OH) ₃ were added thereto, followed by high-speed stirring to prepare a coating slurry. As a lithium composite oxide core particle, 100 g of LiNi _0.84 Co _0.16 O ₂ was used as insoluble Al based on Al element. A lithium composite oxide capable of intercalating / deintercalating lithium ions was prepared in the same manner as in Example 1 except that the ratio of the feed material / soluble Al feed material was coated to 5.

Comparative example  5: Preparation of Positive Electrode Active Material

LiOH (manufacturer: SQM) and _{Ni 0 .80 Co 0 .15 Al 0} .05 (OH) 2 (Tanaka) of 1: 1.08: in a weight ratio of (a precursor Li), but mixed using a mixer temperature increase in the air react A fired body was produced at a total firing time of 20 hours at 750 ° C. and 7 hours at a time of 6 hours and a holding section.

The resulting fired body was slowly cooled and pulverized to prepare a positive electrode active material powder of the lithium metal composite oxide of the present invention. The obtained active material is shown in Table 1 by measuring the C content and preparing a battery using the same, evaluating battery performance.

Comparative example  6: Preparation of positive electrode active material

LiOH (manufacturer: SQM) and Al (OH) ₃ and the Ni _{0 .86 Co 0 .16 (OH)} 2 1: 1.08: in a weight ratio of (Ni + Co + Al Li), but mixed with the air mixer In the heating reaction time of 6 hours, the total firing time was 20 hours in 750 ℃, 7 hours in the holding section, a fired body was produced.

The resulting fired body was slowly cooled and pulverized to prepare a positive electrode active material powder of the lithium metal composite oxide of the present invention. The composition of the active material is made in the C content measurement using the same cell and the _{LiNi 0 .80 Co 0 .15 Al 0} .05 O 2, to assess the cell performance shown in Table 1 below.

Comparative example  7: Preparation of positive electrode active material

For the active material obtained in Comparative Example 6, a coating solution was prepared using only a soluble Al feed material, and coated and calcined to have an Al content of 2000 ppm, thereby preparing a lithium composite oxide capable of intercalating / deintercalating lithium ions.

Coin cell  Produce

95% by weight of the positive electrode active material prepared in Examples 1 to 9 and Comparative Examples 1 to 7, 2.5% by weight of carbon black as a conductive agent, 2.5% by weight of PVDF as a binder, and N-methyl-2 as a solvent (solvent). A positive electrode slurry was prepared by adding to pyrrolidone (NMP) 5.0 wt%. The positive electrode slurry was applied to an aluminum (Al) thin film, which is a positive electrode current collector having a thickness of 20 to 40 μm, vacuum dried, and roll pressed to prepare a positive electrode.

Li-metal was used as the negative electrode.

A coin cell type half cell was manufactured by using a cathode and a Li-metal as the counter electrode and 1.15 M LiPF 6 EC: DMC (1: 1 vol%) as an electrolyte.

Experimental Example : Battery characteristic evaluation

Table 1 shows data of lattice constants, initial formation, rate characteristics, capacity of 1 cycle, and capacity retention after 30 cycles of Examples 1 to 9 and Comparative Examples 1 to 7.

Type of positive electrode active material Lattice constant
(a, Å) Discharge capacity
(mAh / g) efficiency
(%) Rate characteristic
(1.0 / 0.1C,%) 1cycle
Volume 30cycle retention rate
(%) Remarks Example 1 2.866 191.2 88.2 96.2 183.9 95 Example 2 2.864 187.2 88.2 95.2 178.2 94 Example 3 2.868 193.2 89.3 96.4 186.2 92 Example 4 2.868 191.2 90.2 95.2 182.1 88 Example 5 - 190.1 88 97.5 185.4 92 Example 6 - 192.1 88.4 96.9 186.2 91 Example 7 - 190.2 88 96.3 183.1 90 Example 8 - 193.2 90.3 90.7 175.3 88.2 Example 9 - 182.1 90.1 91.2 166.1 91.2 Comparative Example 1 2.870 187.4 87.8 86.3 161.8 78 Comparative Example 2 - - - - - - Ignition Comparative Example 3 - - - - - - Ignition Comparative Example 4 2.869 190 90.4 92.1 175 83 Comparative Example 5 2.862 190.6 90.4 94.4 180 86 Comparative Example 6 2.863 190 89.4 93.2 177 88 Comparative Example 7 2.863 189 89.2 94.8 181 89.5

Examples 1 to 9 showed improved 1-cycle capacity and especially long life compared to Comparative Examples 1 to 6.

Examples 1 to 4 are slightly lower in efficiency compared to Comparative Examples 4 and 5, but it can be seen that the rate characteristics, 1 cycle capacity and long life characteristics are significantly improved.

Comparative Example 1 Ni _{0 .84} Co _{0 .16} to O ₂ Composition _{.16 LiNi 0 .84 Co 0 (OH} ) ₂ were prepared from the precursor does not have the Al doping an oxidizing element was the initial efficiency is low life characteristics is also There is a difference compared to the embodiment.

Comparative Example 2 was coated with only the soluble Al feed material, so that ignition occurred during firing, and thus application was impossible in the process.

In Comparative Example 3, the ratio of the insoluble Al feed material / soluble Al feed material was coated to 1.0 based on the Al element, which is also coated with only the soluble Al feed material, so that ignition occurs during firing, and thus, the process cannot be applied.

In Comparative Example 4, the ratio of insoluble Al feed material / soluble Al feed material was coated to 5 so that the ratio of insoluble Al feed material was higher than that of Example. .

Comparative Example 5 LiNi _{0 .80} examples used the Al-doped precursor Co _{0 .15 0 .05} OAl ₂ O composition initial capacity and efficiency exhibits a high, or low contrast ratio characteristics and embodiments 1cycle capacity, life characteristics have.

Comparative Example 6 is an example obtained a lithium raw material and the Al (OH) ₃ and _{Ni 0 .86 Co 0 .16 (OH} ) 2 were mixed in Comparative Example 5, the firing-effective and 1cycle capacity decreases and, 30cycle life holding property is improved, but It shows lower characteristics compared to the above-described embodiment.

In Comparative Example 7, the cathode material obtained in Comparative Example 6 was treated only with a soluble Al feed material, and it was found that the lifespan characteristics of the example were excellent although the improvement effect was obtained compared to Comparative Example 6.

Experimental Example : Cross section of the prepared cathode active material line Mapping

Cross section line mapping of Example 1 and Comparative Example 6 was performed.

The measurement equipment was an ultra-fine secondary ion mass spectrometer (Nano SIMS50, CAMECA) to perform Al line mapping from the Cs ion source to the bulk surface at the particle surface.

Al of Comparative Example 6 was confirmed that the desired Al doping layer and Al coating layer was well formed as compared to the entire uniformly doped inward from the particle surface.

The present invention is not limited to the above embodiments, but may be manufactured in various forms, and a person skilled in the art to which the present invention pertains has another specific form without changing the technical spirit or essential features of the present invention. It will be appreciated that the present invention may be practiced as. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

Claims (21)

Preparing a coating solution by mixing a first solvent, a first Al feed material soluble in the first solvent, and a second Al feed material insoluble in the first solvent;
Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring to coat the second Al feed material; And
Calcining a lithium composite oxide capable of intercalating / deintercalating lithium ions coated with the first Al supply material and the second Al supply material on the surface;
Wherein the positive electrode active material is a positive electrode active material.
The method of claim 1,
Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring to coat the second Al feed material.
The second Al supply material is coated in an island form on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions, and the first Al supply material intercalates the lithium ions in a film form. The manufacturing method of the positive electrode active material for lithium secondary batteries which is coated on the surface of the lithium composite oxide which can be deintercalated.
The method of claim 1,
Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring to coat the second Al feed material.
Swelling a lithium composite oxide capable of intercalating / deintercalating the lithium ions in a second solvent; And
Injecting a lithium composite oxide capable of intercalating / deintercalating the swelled lithium ions into the coating solution to the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring the Al feed material and the second Al feed material to be coated. 2.
The method of claim 1,
Preparing a coating solution by mixing the first solvent, a first Al feed material soluble in the first solvent, and a second Al feed material insoluble in the first solvent;
Dissolving a first Al feed material soluble in the first solvent in the first solvent; And
And preparing a coating solution by mixing a second Al supply material which is insoluble in the first solvent in a solvent in which the first Al supply material is dissolved.
The method of claim 1,
Preparing a coating solution by mixing the first solvent, a first Al feed material soluble in the first solvent, and a second Al feed material insoluble in the first solvent;
Dissolving a first Al feed material soluble in the first solvent in the first solvent; And
Preparing a coating solution by mixing a second Al supply material insoluble in the first solvent and a lithium supply material in a solvent in which the first Al supply material is dissolved; preparing a positive electrode active material for a lithium secondary battery .
The method of claim 5,
And said lithium supply material is soluble in said first solvent.
The method of claim 3,
The first solvent and the second solvent is the same method for producing a positive electrode active material for a lithium secondary battery.
The method of claim 1,
The first Al feed material soluble in the first solvent is Al-alkoxide, Al-acetate, Al-nitrate, Al-sulfate or a combination thereof.
The method of claim 1,
The second Al feed material insoluble in the first solvent is Al ₂ O ₃ , Al (OH) ₃ , or a combination thereof.
The method of claim 5,
The lithium supply material may be any one of nitrate, carbonate, acetate, oxalate, oxide, hydroxide, and sulfate including lithium. Is selected or a combination thereof, the method for producing a cathode active material for a lithium secondary battery.
The method of claim 1,
A method of manufacturing a cathode active material for a lithium secondary battery, wherein the ratio of the second Al feed material / first Al feed material is 1.5 to 4 based on Al element.
The method of claim 1,
Injecting a lithium composite oxide capable of intercalating / deintercalating lithium ions into the coating solution, the first Al supply material on the surface of the lithium composite oxide capable of intercalating / deintercalating the lithium ions And stirring to coat the second Al feed material; after,
Method for producing a positive electrode active material for a lithium secondary battery further comprising the step of evaporating the first solvent contained in the coating solution.
The method of claim 1,
The lithium composite oxide capable of intercalating / deintercalating the lithium ions is a nickel-cobalt oxide or a nickel-manganese oxide.
The method of claim 1,
Lithium composite oxide capable of intercalating / deintercalating the lithium ions,
Li _a A _{1 - b} X _b D ₂ (0.90? A? 1.8, 0? B? 0.5); _{Li a A 1 - b X b} O 2 - c T c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); LiE _{1 - b} X _b O _{2 - c} D _c (0? B? 0.5, 0? C? 0.05); _{LiE 2 - b X b O 4} - c T c (0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li _a Ni _{1 -b- c} Co _b X _c D _? (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <?? 2); Li _a Ni _{1 -b- c} Co _b X _c O _{2 -α} T _α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2); Li _a Ni _{1 -b- c} Co _b X _c O _{2 - ?} T ₂ (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <? <2); Li _a Ni _{1 -b- c} Mn _b X _c D _? (0.90? A? 1.8, 0? B? 0.5, 0? C? 0.05, 0 <?? 2); Li _a Ni _{1 -b- c} Mn _b X _c O _{2- α} T _α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2); Li _a Ni _{1 -bc} Mn _b X _c O _2-α T ₂ (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2); Li _a Ni _b E _c G _d O ₂ (0.90? A? 1.8, 0? B? 0.9, 0? C? 0.5, 0.001? D? 0.1); Li _a Ni _b Co _c Mn _d G _e O ₂ (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, 0.001 ≤ e ≤ 0.1); Li _a NiG _b O ₂ (0.90? A? 1.8, 0.001? B? 0.1); Li _a CoG _b O ₂ (0.90? A? 1.8, 0.001? B? 0.1); Li _a MnG ′ _b O ₂ (0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1); Li _a Mn ₂ G _b O ₄ (0.90? A? 1.8, 0.001? B? 0.1); Li _a MnG ′ _b PO ₄ (0.90 ≦ a ≦ 1.8, 0.001 ≦ b ≦ 0.1); LiNiVO _4; And Li _(3-f) J ₂ (PO ₄ ) ₃ (0 ≦ f ≦ 2); at least one selected from the group consisting of:
In the above formula, A is selected from the group consisting of Ni, Co, Mn, and combinations thereof; X is selected from the group consisting of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements and combinations thereof; D is selected from the group consisting of O, F, S, P, and combinations thereof; E is selected from the group consisting of Co, Mn, Ni, and combinations thereof; T is selected from the group consisting of F, S, P, and combinations thereof; G is selected from the group consisting of Ni, Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V and combinations thereof; G` is selected from the group consisting of Ni, Al, Cr, Fe, Mg, La, Ce, Sr, V and combinations thereof; Q is selected from the group consisting of Ti, Mo, Mn, Ni, and combinations thereof; Z is selected from the group consisting of Cr, V, Fe, Sc, Y, Ni, and combinations thereof; J is selected from the group consisting of V, Cr, Mn, Co, Ni, Cu, and combinations thereof.
The method of claim 1,
Preparing a coating solution by mixing the first solvent, a first Al feed material soluble in the first solvent, and a second Al feed material insoluble in the first solvent;
Preparing a coating solution by mixing the first solvent, a first Al supply material soluble in the first solvent, a second Al supply material insoluble in the first solvent, and a lithium supply material; Method for producing a positive electrode active material.
The method of claim 2,
Calcining a lithium composite oxide capable of intercalating / deintercalating lithium ions coated with the first Al supply material and the second Al supply material on the surface;
The first Al supply material coated in the form of a film on the surface of the lithium composite oxide is diffused into the lithium composite oxide to form an Al doped layer,
And a second feed material coated in an island form on the surface of the lithium composite oxide to form an Al coating layer on the surface of the lithium composite oxide to form an Al coating layer.
Lithium composite oxide core particles capable of intercalating / deintercalating lithium ions;
An Al doped layer diffused inward from the surface portion of the core particles; And
Cathode active material for a lithium secondary battery comprising an Al coating layer formed on the surface of the core particles.
18. The method of claim 17,
The lattice constant of the X-ray diffraction image (XRD) phase of the positive electrode active material has a value of 2.864 to 2.868 Å.
18. The method of claim 17,
The Al coating layer is a positive electrode active material for a lithium secondary battery that is a coating layer containing Li-Al.
18. The method of claim 17,
A lithium composite oxide core particle capable of intercalating / deintercalating the lithium ions is represented by the following Chemical Formula 1.
[Formula 1]
LiNi _x Co _y M _z O _{2 - t} S _t
(In Formula 1, 0.5 <x <0.9, 0 <y <0.25, 0 ≦ z <0.1, 0 ≦ t <0.1, M is Al, B, Mg, Ti, Mn or Zr, and S is Cl, F or S.)
18. The method of claim 17,
The cathode active material is prepared by the manufacturing method according to claim 1.

Images