Positive electrode active material, secondary battery, and electronic device

Patent metadata

Field	Value
Publication number	US-12244007-B2
Application number	US-202418608249-A
Country	US
Kind code	B2
Filing date	Mar 18, 2024
Priority date	Nov 28, 2019
Publication date	Mar 4, 2025
Grant date	Mar 4, 2025

Abstract

A positive electrode active material in which a capacity decrease caused by charge and discharge cycles is suppressed is provided. Alternatively, a positive electrode active material having a crystal structure that is unlikely to be broken by repeated charging and discharging is provided. The positive electrode active material contains titanium, nickel, aluminum, magnesium, and fluorine, and includes a region where titanium is unevenly distributed, a region where nickel is unevenly distributed, and a region where magnesium is unevenly distributed in a projection on its surface. Aluminum is preferably unevenly distributed in a surface portion, not in the projection, of the positive electrode active material.

First claim

What is claimed is:

1. A positive electrode active material comprising a particle comprising oxygen, cobalt, lithium, magnesium, titanium, nickel, aluminum, and fluorine,
wherein the particle comprises a superficial portion, an inner portion, a depression, and a projection on the superficial portion,
wherein the particle comprises a region where a titanium concentration in the depression is higher than a titanium concentration in the superficial portion,
wherein the particle comprises a region where a titanium concentration in the projection is higher than the titanium concentration in the superficial portion,
wherein the particle comprises a region where a magnesium concentration in the projection is higher than a magnesium concentration in the superficial portion,
wherein the particle comprises a region where a nickel concentration in the projection is higher than a nickel concentration in the superficial portion,
wherein the particle comprises a region where a fluorine concentration in the projection in the projection is higher than a fluorine concentration in the superficial portion, and
wherein the particle comprises a region where an aluminum concentration in the superficial portion is higher than an aluminum concentration in the projection.

2. The positive electrode active material according to claim 1 ,
wherein the particle comprises a region where a magnesium concentration in the depression is higher than the magnesium concentration in the superficial portion, and
wherein the particle comprises a region where a fluorine concentration in the depression is higher than the fluorine concentration in the superficial portion.

3. The positive electrode active material according to claim 1 ,
wherein the depression comprises a portion,
wherein a depth of the portion is more than 100 nm, and
wherein a width of the portion is more than 20 nm.

4. The positive electrode active material according to claim 1 ,
wherein the projection comprises a portion, and
wherein a height of the projection is greater than 50 nm.

5. The positive electrode active material according to claim 1 , wherein the particle comprises a region where a cobalt concentration in the projection is lower than a cobalt concentration in the inner portion.

6. A secondary battery comprising the positive electrode active material according to claim 1 .

7. An electronic device comprising the secondary battery according to claim 6 .

8. A positive electrode active material comprising a particle comprising oxygen, cobalt, lithium, magnesium, titanium, nickel, aluminum, and fluorine,
wherein the particle comprises a superficial portion, an inner portion, a depression, and a projection on the superficial portion,
wherein the particle comprises a region where a titanium concentration in the depression is higher than a titanium concentration in the inner portion,
wherein the particle comprises a region where a titanium concentration in the projection is higher than the titanium concentration in the inner portion,
wherein the particle comprises a region where a magnesium concentration in the projection is higher than a magnesium concentration in the inner portion,
wherein the particle comprises a region where a nickel concentration in the projection is higher than a nickel concentration in the inner portion,
wherein the particle comprises a region where a fluorine concentration in the projection is higher than a fluorine concentration in the inner portion, and
wherein the particle comprises a region where an aluminum concentration in the superficial portion is higher than an aluminum concentration in the projection.

9. The positive electrode active material according to claim 8 ,
wherein the depression comprises a portion,
wherein a depth of the portion is greater than 100 nm, and
wherein a width of the portion is greater than 20 nm.

10. The positive electrode active material according to claim 8 ,
wherein the projection comprises a portion, and
wherein a height of the projection is greater than 50 nm.

11. The positive electrode active material according to claim 8 , wherein the particle comprises a region where a cobalt concentration in the projection is lower than a cobalt concentration in the inner portion.

12. A secondary battery comprising the positive electrode active material according to claim 8 .

13. An electronic device comprising the secondary battery according to claim 12 .

Assignees

• Semiconductor Energy Lab

Inventors

• Momma Yohei
• Kadoma Hiroshi
• Komatsu Yoshihiro
• Saga Shiori
• Yamazaki Shunpei

Classifications

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/582

  Halogenides · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title