Positive electrode active material particle and method for manufacturing positive electrode active material particle

Patent metadata

Field	Value
Publication number	US-2018145368-A1
Application number	US-201715810989-A
Country	US
Kind code	A1
Filing date	Nov 13, 2017
Priority date	Nov 24, 2016
Publication date	May 24, 2018
Grant date	—

Abstract

Positive electrode active material particles that inhibit a decrease in capacity due to charge and discharge cycles are provided. A high-capacity secondary battery, a secondary battery with excellent charge and discharge characteristics, or a highly-safe or highly-reliable secondary battery is provided. A novel material, active material particles, and a storage device are provided. The positive electrode active material particle includes a first region and a second region in contact with the outside of the first region. The first region contains lithium, oxygen, and an element M that is one or more elements selected from cobalt, manganese, and nickel. The second region contains the element M, oxygen, magnesium, and fluorine. The atomic ratio of lithium to the element M (Li/M) measured by X-ray photoelectron spectroscopy is 0.5 or more and 0.85 or less. The atomic ratio of magnesium to the element M (Mg/M) is 0.2 or more and 0.5 or less.

First claim

What is claimed is:

1 . A positive electrode active material particle comprising:
a first region comprising Li, an element M, and O; and a second region in contact with an outside of the first region, the second region comprising the element M, O, Mg and F, wherein the element M is one or more elements selected from Co, Mn and Ni, wherein an atomic ratio of Li to the element M in the second region is higher than or equal to 0.5 and lower than or equal to 0.85 in X-ray photoelectron spectroscopy, and wherein an atomic ratio of Mg to the element M in the second region is higher than or equal to 0.2 and lower than or equal to 0.5 in X-ray photoelectron spectroscopy.

2 . The positive electrode active material particle according to claim 1 , wherein a thickness of the second region is greater than or equal to 0.5 nm and less than or equal to 50 nm.

3 . The positive electrode active material particle according to claim 1 ,
wherein the first region has a layered rock-salt crystal structure, and wherein the second region has a rock-salt crystal structure.

4 . The positive electrode active material particle according to claim 1 ,
wherein a crystal structure of the first region is represented by a space group R-3m, and wherein a crystal structure of the second region is represented by a space group Fm-3m.

5 . The positive electrode active material particle according to claim 1 , wherein an atomic ratio of F to the element M in the second region is higher than or equal to 0.02 and lower than or equal to 0.15 in X-ray photoelectron spectroscopy.

6 . The positive electrode active material particle according to claim 1 , wherein the element M is cobalt.

7 . An active material particle comprising:
an inner region comprising Li, an element M, and O, the inner region comprising a first crystal having a layered rock-salt crystal structure; and an outer region comprising the element M, 0 , Mg and F, wherein the element M is one or more elements selected from Co, Mn and Ni, wherein an atomic ratio of Li to the element M in the outer region is higher than or equal to 0.5 and lower than or equal to 0.85, and wherein an atomic ratio of Mg to the element M in the outer region is higher than or equal to 0.2 and lower than or equal to 0.5.

8 . The active material particle according to claim 7 , wherein the atomic ratio of Li to the element M in the outer region and the atomic ratio of Mg to the element M in the outer region are measured by X-ray photoelectron spectroscopy.

9 . The active material particle according to claim 7 , wherein a thickness of the outer region is greater than or equal to 0.5 nm and less than or equal to 50 nm.

10 . The active material particle according to claim 7 , wherein the outer region comprises a second crystal having a rock-salt crystal structure.

11 . The active material particle according to claim 10 ,
wherein a crystal structure of the first crystal belongs to a space group R-3m, and wherein a crystal structure of the second crystal belongs to a space group Fm-3m.

12 . The active material particle according to claim 7 , wherein an atomic ratio of F to the element M in the outer region is higher than or equal to 0.02 and lower than or equal to 0.15.

13 . The active material particle according to claim 7 , wherein the element M is cobalt.

14 . A method for manufacturing an active material particle, comprising the step of:
making an active material particle from raw materials comprising Li, an element M, O, Mg and F, wherein the active material particle comprises:
a first region comprising Li, the element M, and O;
a second region in contact with an outside of the first region, the second region comprising the element M, O, Mg and F,
wherein the element M is one or more elements selected from Co, Mn and Ni, and wherein an atomic ratio of Li to the element M in the raw materials is higher than 1.02 and lower than 1.05.

15 . The method for manufacturing an active material particle, according to claim 14 , wherein an atomic ratio of Mg to the element M in the raw materials is higher than or equal to 0.005 and lower than or equal to 0.05.

16 . The method for manufacturing an active material particle, according to claim 14 , wherein an atomic ratio of F to the element M in the raw materials is higher than or equal to 0.01 and lower than or equal to 0.1.

17 . The method for manufacturing an active material particle, according to claim 14 ,
wherein the raw materials comprise:
a first compound comprising Li;
a second compound comprising the element M; and
a third compound comprising Mg.

18 . The method for manufacturing an active material particle, according to claim 14 , wherein a thickness of the second region is greater than or equal to 0.5 nm and less than or equal to 50 nm.

Assignees

• Semiconductor Energy Lab

Inventors

• Ochiai Teruaki
• Kawakami Takahiro
• Mikami Mayumi
• Momma Yohei
• TSURUTA Ayae
• Takahashi Masahiro

Classifications

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/02

  Electrodes composed of, or comprising, active material · 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

• H01M10/0525 Primary

  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