# US 2017/0288226 A1 · Lithium-ion secondary battery

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- Number: US 2017/0288226 A1
- Document ID: US20170288226A1
- Status: Published application
- Kind: A1
- Application number: 15/463,207
- Filed: 2017-03-20
- Published: 2017-10-05
- Earliest claimed: 2016-03-30
- Assignees: Sumitomo Osaka Cement Co., Ltd.
- Applicants: Sumitomo Osaka Cement Co., Ltd.
- Inventors: Masataka OYAMA; Takao KITAGAWA
- Web page: https://patentgrep.com/patent/US20170288226A1

## CPC

- H01M 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines}
- H01M 4/136: Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
- H01M 4/366: {as layered products}
- H01M 4/625: {Carbon or graphite}
- 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
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A lithium-ion secondary battery including a cathode, an anode, and an electrolyte, in which the lithium-ion secondary battery includes inorganic phosphate particles, and the cathode includes cathode active material particles which include central particles made of LixAyMzPO4 (0≦x≦1.1, 0.8≦y≦1.1, and 0≦z≦0.2; here, A represents at least one element selected from the group consisting of Fe, Mn, Co, and Ni, and M represents at least one element selected from the group consisting of Mg, Ca, Co, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, and rare earth elements) and a carbonaceous film that coats surfaces of the central particles.

## Claims

### Claim 1

A lithium-ion secondary battery comprising:
a cathode;
an anode; and
an electrolyte,
wherein the lithium-ion secondary battery includes inorganic phosphate particles, and the cathode includes cathode active material particles which include central particles made of LixAyMzPO4 (0≦x≦1.1, 0.8≦y≦1.1, and 0≦z≦0.2; here, A represents at least one element selected from the group consisting of Fe, Mn, Co, and Ni, and M represents at least one element selected from the group consisting of Mg, Ca, Co, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, and rare earth elements) and a carbonaceous film that coats surfaces of the central particles.

### Claim 2 (depends on 1)

The lithium-ion secondary battery according to claim 1,
wherein an average primary particle diameter of the cathode active material particles is 10 nm or more and 700 nm or less, and an average primary particle diameter of the inorganic phosphate particles is 0.5 μm or more and 75 μm or less.

### Claim 3 (depends on 1)

The lithium-ion secondary battery according to claim 1,
wherein a content of the inorganic phosphate particles in the cathode is 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the cathode active material particles.

### Claim 4 (depends on 1)

The lithium-ion secondary battery according to claim 1,
wherein the cathode is made of composite particles in which cathode active material particles are attached to inorganic phosphate particle surfaces.

### Claim 5 (depends on 1)

The lithium-ion secondary battery according to claim 1,
wherein the inorganic phosphate particles contain at least one element selected from the group consisting of alkali metals and alkali earth metals, and a transition metal/phosphorus ratio (substance amount ratio) is 0.5 or lower.

### Claim 6 (depends on 1)

The lithium-ion secondary battery according to claim 1,
wherein the inorganic phosphate particles are represented by LiαPβOγ (0<α≦3, 0β≦2, 0<γ≦4, 0.5≦α/β≦3.5).