# US 2019/0245202 A1 · Cathode active material for lithium ion secondary battery, and process for its production

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- Number: US 2019/0245202 A1
- Document ID: US20190245202A1
- Status: Published application
- Kind: A1
- Application number: 16/386,852
- Filed: 2019-04-17
- Published: 2019-08-08
- Earliest claimed: 2011-09-30
- Assignees: Sumitomo Chemical Company, Limited
- Applicants: Sumitomo Chemical Co., Ltd
- Inventors: Takeshi KAWASATO; Kentaro Tsunozaki; Haisheng Zeng; Yasuyuki Takimoto; Toshio Suzuki; Tegi Ri
- Web page: https://patentgrep.com/patent/US20190245202A1

## CPC

- H01M 4/366: {as layered products}
- C01D 15/02: Oxides; Hydroxides
- H01M 4/483: {for non-aqueous cells (H01M4/485 takes precedence)}
- 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
- H01M 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines}
- C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram
- C01P 2004/80: Particles consisting of a mixture of two or more inorganic phases
- C01P 2006/12: Surface area
- C01P 2006/40: Electric properties
- 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
- C01D: COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides C01B17/22; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia and cyanogen, containing nitrogen and other non-metals C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; phosphides 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; cyanides C01C3/08; salts of cyanic acid C01C3/14; 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

To provide a cathode active material for a lithium ion secondary battery excellent in the cycle characteristics and rate characteristics even when charging is conducted at a high voltage. A cathode active material for a lithium ion secondary battery, which comprises particles (III) having a covering layer comprising a metal oxide (I) containing at least one metal element selected from the group consisting of elements in Groups 3 and 13 of the periodic table and lanthanoid elements, and a compound (II) containing Li and P, on the surface of a lithium-containing composite oxide comprising lithium and a transition metal element, wherein the atomic ratio of said P to said metal element (P/metal element) contained within 5 nm of the surface layer of the particles (III) is from 0.03 to 0.45.

## Claims

### Claim at position 1

1: A cathode active material for a lithium ion secondary battery, comprising:
particles (III) which comprise: a lithium-containing composite oxide; and a covering layer provided on the surface of the lithium-containing composite oxide,
wherein the covering layer comprises: a metal oxide (I) comprising at least one metal element selected from the group consisting of elements in Groups 3 and 13 of the periodic table and lanthanoid elements; and a compound (II) comprising Li and P,
wherein the metal oxide (I) is crystalline,
wherein the atomic ratio of the P to the at least one metal element (P/the at least one metal element) contained within 5 nm of the surface layer of the particles (III) is from 0.03 to 0.45,
wherein the lithium-containing composite oxide is represented by formula (2-1):
Li(LixMnyMe′z)OpFq (2-1),
wherein Me′ is at least one member selected from the group consisting of Co, Ni, Cr, Fe, Al, Ti, Zr, and Mg: 0.09<x<0.3; y>0; z>0; 1.9<p<2.1; 0≤q≤0.1; 0.4≤y/(y+z)≤0.8; x+y+z=1; and 1.2<(1+x)/(y+z), and
wherein in an X-ray diffraction measurement of the lithium-containing composite oxide using CuKα ray as an X-ray source, a peak is observed within a range of 2θ=20 to 25°.

### Claim at position 2 (depends on 1)

2: The cathode active material according to claim 1, wherein the at least one metal element is at least one metal element selected from the group consisting of Al, Y, Ga, In, La, Pr, Nd, Gd, Dy, Er and Yb.

### Claim at position 3 (depends on 1)

3: The cathode active material according to claim 1, wherein the compound (II) is Li3PO4.

### Claim at position 4 (depends on 1)

4: The cathode active material according to claim 1, wherein the atomic ratio of the P to the at least one metal element (P/the at least one metal element) contained within 5 nm of the surface layer of the particles (III) is from 0.10 to 0.40.

### Claim at position 5 (depends on 1)

5: The cathode active material according to claim 1, wherein the molar ratio of the at least one metal element to the lithium-containing composite oxide is from 0.001 to 0.03.

### Claim at position 6 (depends on 1)

6: A cathode for a lithium ion secondary battery comprising:
the cathode active material as defined in claim 1; and
a binder.

### Claim at position 7 (depends on 6)

7: A lithium ion secondary battery comprising:
the cathode as defined in claim 6;
an anode; and
a non-aqueous electrolyte.

### Claim at position 8 (depends on 1)

8: The cathode active material according to claim 1, wherein the at least one metal element in the covering layer is present in a larger amount within a range up to 30 nm from the surface of the particle (III) than at the center of the particle (III).

### Claim at position 9 (depends on 1)

9: The cathode active material according to claim 1, wherein in formula (2-1), 1.25≤(1+x)/(y+z)≤1.75 is satisfied.

### Claim at position 10 (depends on 1)

10: The cathode active material according to claim 1, wherein the lithium-containing composite oxide is represented by formula (2-2):
Li(LixMnyNivCow)Op (2-2),
wherein 0.09<x<0.3, 0.36<y<0.73, 0<v<0.32, 0<w<0.32, 1.9<p<2.1, and x+y+v+w=1.

### Claim at position 11 (depends on 1)

11: The cathode active material according to claim 1, wherein in formula (2-1), 0.16≤x<0.3 is satisfied.

### Claim at position 12 (depends on 18)

12: The cathode active material according to claim 18, wherein in formula (2-1), 2≤p<2.1 and q=0 are satisfied.

### Claim at position 13 (depends on 1)

13: The cathode active material according to claim 1, wherein the compound (II) is crystalline.