# US 12,015,154 B2 · Cathode active material for lithium ion secondary battery and lithium ion secondary battery

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- Number: US 12,015,154 B2
- Document ID: US12015154B2
- Status: Granted
- Kind: B2
- Application number: 17/264,357
- Filed: 2019-07-03
- Published: 2021-09-30
- Granted: 2024-06-18
- Earliest claimed: 2018-08-02
- Assignees: Sumitomo Metal Mining Co., Ltd.; Toyota Jidosha Kabushiki Kaisha
- Applicants: Sumitomo Metal Mining Co., Ltd.; Toyota Jidosha Kabushiki Kaisha
- Inventors: Satoshi Kanada; Tetsutaro Hayashi; Ryuta Sugiura
- Web page: https://patentgrep.com/patent/US12015154B2

## CPC

- 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
- C01G 53/84: Hydroxides
- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/38: of elements or alloys
- H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
- H01M 4/52: of nickel, cobalt or iron
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/028: {Positive electrodes}
- 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)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

To provide a cathode active material capable of reducing cathode resistance of a secondary battery by enhancing electron conductivity thereof without reducing discharge capacity of the secondary battery. Lanthanum compound particles each having a perovskite-type structure are dispersed on surfaces of secondary particles of a lithium transition metal-containing composite oxide and/or in gaps or grain boundaries between primary particles thereof. The lanthanum compound particles have a cross-sectional average particle size of 0.70 μm or less. The number of lanthanum compound particles present per unit area of the cross sections of the secondary particles is 0.03 particles/μm2 to 0.10 particles/μm2, and the number of lanthanum compound particles present per unit area of the surfaces of the secondary particles is 0.01 particles/μm2 to 0.25 particles/μm2. The content of lanthanum with respect to the entire cathode active material is within a range of 0.1% by mass to 5% by mass.

## Claims

### Claim 1

A cathode active material for a lithium ion secondary battery, the cathode active material comprising a lithium transition metal-containing oxide configured by secondary particles each formed of a plurality of primary particles, wherein lanthanum compound particles each having a perovskite-type structure are dispersed on surfaces of the secondary particles and/or in gaps or grain boundaries between the primary particles, and the lanthanum compound particles have a cross-sectional average particle size of 0.70 μm or less.

### Claim 2 (depends on 1)

The cathode active material for a lithium ion secondary battery according to claim 1, wherein a number of the lanthanum compound particles present per unit area of the surfaces of the secondary particles is within a range of 0.01 particles/μm2 to 0.25 particles/μm2.

### Claim 3 (depends on 1)

The cathode active material for a lithium ion secondary battery according to claim 1, wherein a number of the lanthanum compound particles present per unit area of cross sections of the secondary particles is within a range of 0.03 particles/μm2 to 0.10 particles/μm2.

### Claim 4 (depends on 1)

The cathode active material for a lithium ion secondary battery according to claim 1, wherein the lanthanum compound particles have a surface average particle size of 0.50 μm or less.

### Claim 5 (depends on 1)

The cathode active material for a lithium ion secondary battery according to claim 1, wherein a content of lanthanum with respect to an entire cathode active material is within a range of 0.1% by mass to 5% by mass.

### Claim 6 (depends on 1)

The cathode active material for a lithium ion secondary battery according to claim 1, wherein the lanthanum compound particles contain one or more metal elements selected from the group consisting of nickel, cobalt, and manganese.

### Claim 7 (depends on 1)

A lithium ion secondary battery comprising a cathode, an anode, and an electrolyte, wherein the cathode active material for a lithium ion secondary battery according to claim 1 is used as a cathode material for the cathode.