Positive electrode active material, secondary battery, and electronic device

Patent metadata

Field	Value
Publication number	US-2025201821-A1
Application number	US-202519068105-A
Country	US
Kind code	A1
Filing date	Mar 3, 2025
Priority date	Nov 28, 2019
Publication date	Jun 19, 2025
Grant date	—

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, and nickel, and aluminum,
wherein the particle comprises a superficial portion, an inner portion, and a projection on the superficial portion, wherein the projection comprises a high fluorine concentration region and a high impurity metal concentration region, wherein a fluorine concentration in the high fluorine concentration region is higher than a fluorine concentration in the superficial portion and the high impurity metal concentration region, wherein a magnesium concentration in the high impurity metal concentration region is higher than a magnesium concentration in the superficial portion and the high fluorine concentration region, wherein a titanium concentration in the high impurity metal concentration region is higher than a titanium concentration in the superficial portion and the high fluorine concentration region, wherein a nickel concentration in the high impurity metal concentration region is higher than a nickel concentration in the superficial portion and the high fluorine concentration region, and wherein an aluminum concentration in the superficial portion is higher than an aluminum concentration in the projection.

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

3 . The positive electrode active material according to claim 1 , wherein the particle further comprises a depression.

4 . The positive electrode active material according to claim 2 , wherein the particle further comprises a depression.

5 . The positive electrode active material according to claim 3 , wherein a titanium concentration in the depression is higher than the titanium concentration in the inner portion.

6 . The positive electrode active material according to claim 4 , wherein a titanium concentration in the depression is higher than the titanium concentration in the inner portion.

7 . The positive electrode active material according to claim 3 ,
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.

8 . The positive electrode active material according to claim 4 ,
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.

9 . The positive electrode active material according to claim 3 ,
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.

10 . The positive electrode active material according to claim 4 ,
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.

11 . 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.

12 . The positive electrode active material according to claim 2 ,
wherein the projection comprises a portion, and wherein a height of the projection is greater than 50 nm.

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

14 . A secondary battery comprising the positive electrode active material according to claim 2 .

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

16 . An electronic device comprising the secondary battery according to claim 14 .

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