# US 2017/0288262 A1 · Method for producing positive active material precursor and positive active material for lithium secondary batteries, exhibiting concentration gradient, and positive active material precursor and positive active material for lithium secondary batteries, exhibiting concentration gradient, produced by same

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- Number: US 2017/0288262 A1
- Document ID: US20170288262A1
- Status: Published application
- Kind: A1
- Application number: 15/630,014
- Filed: 2017-06-22
- Published: 2017-10-05
- Earliest claimed: 2014-12-31
- Assignees: Ecopro Bm Co., Ltd.
- Applicants: Ecopro Bm Co., Ltd.
- Inventors: Moon Ho CHOI; Jik Soo KIM; Jin Kyeong YUN; Suk Yong JEON; Jae Yong JUNG; Yong Chul SUNG
- Web page: https://patentgrep.com/patent/US20170288262A1

## CPC

- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- C01G 53/44: containing manganese
- C01G 53/84: Hydroxides
- H01M 4/366: {as layered products}
- H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
- H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- C01P 2002/50: Solid solutions
- C01P 2002/85: by XPS, EDX or EDAX data
- C01P 2004/03: obtained by SEM
- C01P 2006/40: Electric properties
- H01M 2004/028: {Positive electrodes}
- Y02E 60/10: Energy storage using batteries
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

Disclosed are a method for manufacturing a lithium secondary battery positive active material exhibiting a concentration gradient and a lithium secondary battery positive active material exhibiting a concentration gradient, manufactured by the method, and more particularly, a method for manufacturing a lithium secondary battery positive active material exhibiting a concentration gradient and a lithium secondary battery positive active material exhibiting a concentration gradient, manufactured by the method, the method being characterized by forming a barrier layer so as to maintain a concentration gradient layer even in case of thermal diffusion by a subsequent thermal treatment process.

## Claims

### Claim 1

A method for manufacturing a lithium secondary battery positive active material having a concentration gradient layer, the method comprising:
inputting a chelating agent solution into a reactor;
continuously inputting a core forming solution, a chelating agent solution, and an alkaline solution into the reactor at the same time and obtaining a spherical precipitate forming a core layer;
continuously inputting a barrier layer forming solution, a chelating agent solution, and an alkaline solution into the reactor at the same time and obtaining a spherical precipitate forming a barrier layer;
preparing a shell forming solution and continuously mixedly inputting a chelating agent solution, an alkaline solution, the core forming solution, and the shell forming solution into the reactor at the same time and obtaining a precipitate, which forms the concentration gradient layer where concentration of nickel-manganese-cobalt varies gradually and relatively, on a surface of the barrier layer;
drying the precipitate; and
thermally treating the dried precipitate.

### Claim 2 (depends on 1)

The method of claim 1, wherein the barrier layer forming solution includes Ni and Mn.

### Claim 3 (depends on 1)

The method of claim 1, wherein the barrier layer forming solution includes Ni and Mn in a mole ratio of 30:70 to 70:30.

### Claim 4 (depends on 1)

The method of claim 1, wherein the barrier layer forming solution includes Ni and Mn in a mole ratio of 50:50.

### Claim 5 (depends on 1)

The method of claim 1, wherein the core forming solution includes a mole ratio of Ni:Co:Mn=a:b:1−(a+b)(0.7≦a≦1.0, 0≦b≦0.2).

### Claim 6 (depends on 1)

The method of claim 1, wherein the shell forming solution includes a mole ratio of Ni:Co:Mn=a:b:1−(a+b)(0.3≦a≦0.6, 0≦b≦0.4).

### Claim 7 (depends on 1)

The method of claim 1, wherein the preparing of the shell forming solution and the continuously mixedly inputting of the chelating agent solution, the alkaline solution, the core forming solution, and the shell forming solution into the reactor at the same time comprises:
mixing the core forming solution and the shell forming solution in an additional preliminary reactor and continuously inputting the mixed solution into the reactor at the same time.

### Claim 8 (depends on 1)

The method of claim 1, further comprising:
continuously mixedly putting a shell forming solution, a chelating agent solution, and an alkaline solution into the reactor at the same time and obtaining a spherical precipitate forming a shell layer between the preparing of the shell forming solution and the continuously mixedly putting of the chelating agent solution, the alkaline solution, the core forming solution, and the shell forming solution into the reactor at the same time, and the drying of the precipitate.

### Claim 9 (depends on 1)

A lithium secondary battery positive active material precursor, having a concentration gradient layer, manufactured by the method according to claim 1.

### Claim 10 (depends on 9)

The lithium secondary battery positive active material precursor of claim 9, wherein a barrier layer has a thickness equal to or larger than 0.01 μm and smaller than 2.0 μm, or equal to or larger than 1% and smaller than 20% of a volume of particles.

### Claim 11 (depends on 9)

The lithium secondary battery positive active material precursor of claim 9, wherein a size of a primary particle is reduced in 10 to 40% from a size of a primary particle of a positive active material precursor having the same composition without a barrier layer.

### Claim 12 (depends on 9)

A method for manufacturing a lithium secondary battery positive active material having a concentration gradient layer, the method comprising:
mixing a lithium secondary battery positive active material precursor having a concentration gradient layer according to claim 9 with a lithium compound; and
thermally treating the mixture for 10 to 25 hours in oxidation atmosphere of air or oxygen at 750 to 1000° C.

### Claim 13 (depends on 12)

A lithium secondary battery positive active material, having a concentration gradient layer, manufactured by the method according to claim 12.