# US 10,374,231 B2 · Lithium secondary battery

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- Number: US 10,374,231 B2
- Document ID: US10374231B2
- Status: Granted
- Kind: B2
- Application number: 14/967,845
- Filed: 2015-12-14
- Published: 2016-06-16
- Granted: 2019-08-06
- Earliest claimed: 2014-12-16
- Assignees: SK Innovation Co., Ltd.
- Applicants: SK Innovation Co., Ltd.
- Inventors: Kyung-Bin Yoo; Kook-Hyun Han; Duck-Chul Hwang
- Web page: https://patentgrep.com/patent/US10374231B2

## CPC

- H01M 4/485: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence)
- C01G 53/42: containing alkali metals, e.g. LiNiO2
- C01G 53/506: with the molar ratio of nickel with respect to all the metals other than alkali metals higher than or equal to 0.8, e.g. Li(MzNixCoyMn1-x-y-z)O2 with x ≥ 0.8
- H01M 4/364: {as mixtures}
- 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 2002/52: containing elements as dopants
- C01P 2002/54: one element only
- C01P 2004/03: obtained by SEM
- C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer
- C01P 2006/40: Electric properties
- H01M 4/362: {Composites}
- H01M 10/052: Li-accumulators
- Y02E 60/10: Energy storage using 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

## Abstract

The present invention relates to a lithium secondary battery, and more specifically, to a lithium secondary battery including a cathode, an anode and a non-aqueous electrolyte solution, where the cathode includes a cathode active material including a lithium-metal oxide which is doped with a transition metal and includes at least one type of metal having a concentration gradient region between a central portion and a surface portion, and thus having a significantly increased charge/discharge capacity and output at a low temperature to exhibit excellent properties in the low-temperature environment.

## Claims

### Claim 1

A lithium secondary battery, comprising:
a cathode;
an anode; and
a non-aqueous electrolyte solution,
wherein the cathode includes a cathode active material including a lithium-metal oxide which is doped with a dopant element,
wherein the lithium-metal oxide is represented by Formula 1 below,
LixM1aM2bM3cOy Formula 1
wherein M1, M2 and M3 are selected from a group consisting of Ni, Co, Mn, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga and B,
0<x≤1.1, 2≤y≤2.02, 0<a<1, 0<b<1, 0<c<1, and 0<a+b+c≤1,
wherein the cathode active material comprises
a central portion within 0.1 μm to 0.2 μm radius from a center of the cathode active material;
a surface portion within 0.1 μm but not less than 0.05 μm from an outmost portion of the cathode active material; and
an intermediate region between the central portion and the surface portion, the intermediate region comprising a concentration gradient region wherein M1 and M3 have a concentration gradient in a direction from the central portion to the surface portion, and a non-concentration gradient region wherein M1 and M3 do not have a concentration gradient in a direction from the central portion to the surface portion; and
wherein M2 has a constant concentration throughout the cathode active material from the central portion to the surface portion.

### Claim 2 (depends on 1)

The lithium secondary battery of claim 1, wherein the concentration of M3 is increased within the concentration gradient region in the direction from the central portion to the surface portion, and the concentration of M1 is decreased within the concentration gradient region in the direction from the central portion to the surface portion.

### Claim 3 (depends on 1)

The lithium secondary battery of claim 1, wherein the concentrations of M3 and M1 are constant within the central portion and the surface portion.

### Claim 4 (depends on 1)

The lithium secondary battery of claim 1, wherein the M1, M2 and M3 are Ni, Co and Mn, respectively.

### Claim 5 (depends on 1)

The lithium secondary battery of claim 1, wherein the non-concentration gradient region comprises a first non-concentration gradient region between the central portion and the concentration gradient region and a second non-concentration gradient region between the concentration gradient region and, the surface portion.

### Claim 6 (depends on 1)

The lithium secondary battery of claim 1, wherein a concentration of the dopant element ranges from 1,000 to 5,000 ppm.

### Claim 7 (depends on 1)

The lithium secondary battery of claim 1, wherein the concentration of M3 at the central portion and the concentration of M3 at the surface portion are different from each other, and
the concentration of M1 at the central portion and the concentration of M1 at the surface portion are different from each other.

### Claim 8 (depends on 1)

The lithium secondary battery of claim 1, wherein the dopant element is one or more selected from the group consisting of Ti, Zr, Mg, Al, V, B, Na, Ca, Cr, Cu, Zn, Ge, Sr, Ba, Nb and Ga.

### Claim 9 (depends on 1)

The lithium secondary battery of claim 1, wherein the M1 is Ni, and 0.6≤a≤0.95 and 0.05≤b+c≤0.4.

### Claim 10 (depends on 1)

The lithium secondary battery of claim 1, wherein the M1 is Ni, and 0.7≤a≤0.9 and 0.1≤b+c≤0.3.

### Claim 11 (depends on 1)

The lithium secondary battery of claim 1, wherein primary particles including the lithium-metal oxide are rod-type particles.

### Claim 12 (depends on 1)

The lithium secondary battery of claim 1, wherein the surface portion has a width of 0.1 μm from an outmost portion of the cathode active material.