POSITIVE ELECTRODE ACTIVE MATERIAL, POSITIVE ELECTRODE, LITHIUM-ION SECONDARY BATTERY, AND METHOD OF PRODUCING POSITIVE ELECTRODE ACTIVE MATERIAL

• US 20190319271A1
• Filed: 03/13/2019
• Published: 10/17/2019
• Est. Priority Date: 04/16/2018
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: YAMAMOTO, Kunimitsu, MAKIMURA, Yoshinari
• Granted Patent: US 11,296,327 B2
• Time in Patent Office: Days
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2004/028 Positive electrodes
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/1393 of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/1397 of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: 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
• CPC Class Codes: H01M 4/5835 Comprising fluorine or fluoride salts
• CPC Class Codes: H01M 4/628 Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A positive electrode active material contains at least: fluorine in an amount not lower than 0.08 mass %; carbon in an amount not lower than 0.02 mass %; and lithium-metal composite oxide particles making up the remainder. The lithium-metal composite oxide particles contain nickel in an amount not lower than 60 mol % of the total amount of metallic elements. At least a partial amount of each of the fluorine and the carbon is present on surfaces of the lithium-metal composite oxide particles.

Claims

1. A positive electrode active material for a lithium-ion secondary battery, the positive electrode active material comprising at least:

fluorine in an amount not lower than 0.08 mass %;

carbon in an amount not lower than 0.02 mass %; and

lithium-metal composite oxide particles making up the remainder,

the lithium-metal composite oxide particles containing nickel in an amount not lower than 60 mol % of the total amount of metallic elements,

at least a partial amount of each of the fluorine and the carbon being present on surfaces of the lithium-metal composite oxide particles.

2. The positive electrode active material according to claim 1, wherein the positive electrode active material comprises fluorine in an amount not higher than 0.61 mass %.

3. The positive electrode active material according to claim 1, wherein the lithium-metal composite oxide particles have a composition represented by the following formula (I):

LiNi_xCo_yAl_zO₂  

 

(I)

where x, y, and z satisfy the following relations;

0.6≤

x≤

0.9;

x+y+z=1; and

y≥

z.

4. The positive electrode active material according to claim 1, wherein the lithium-metal composite oxide particles contain nickel in an amount not lower than 80 mol % of the total amount of metallic elements.

5. A positive electrode including at least the positive electrode active material according to claim 1.

6. A lithium-ion secondary battery including at least the positive electrode according to claim 5.

7. A method of producing a positive electrode active material for a lithium-ion secondary battery, the method comprising at least:

preparing lithium-metal composite oxide particles;

mixing the lithium-metal composite oxide particles with a fluorocarbon material to prepare a mixture; and

heating the mixture in an inert atmosphere to produce the positive electrode active material,

the lithium-metal composite oxide particles containing nickel in an amount not lower than 60 mol % of the total amount of metallic elements,

a content of the fluorocarbon material in the mixture being determined so that the positive electrode active material contains at least fluorine in an amount not lower than 0.08 mass %, carbon in an amount not lower than 0.02 mass %, and the lithium-metal composite oxide particles making up the remainder.

8. The method of producing a positive electrode active material according to claim 7, wherein

the fluorocarbon material is polytetrafluoroethylene, and

the mixture is heated at a temperature not lower than a temperature at which polytetrafluoroethylene breaks down to produce the positive electrode active material.

9. The method of producing a positive electrode active material according to claim 8, wherein the mixture contains polytetrafluoroethylene in an amount not lower than 0.10 mass % of the amount of the mixture.

10. The method of producing a positive electrode active material according to claim 8, wherein the mixture contains polytetrafluoroethylene in an amount not higher than 0.80 mass % of the amount of the mixture.