Positive electrode active material, lithium ion secondary battery, and method of producing positive electrode active material

Patent metadata

Field	Value
Publication number	US-10971720-B2
Application number	US-201815953947-A
Country	US
Kind code	B2
Filing date	Apr 16, 2018
Priority date	Apr 27, 2017
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

A positive electrode active material includes secondary particles. The secondary particles include a plurality of primary particles. The primary particles include a lithium-containing composite metal oxide. Inside the secondary particles, an electron conducting oxide is disposed at at least a part of a grain boundary between the primary particles. The electron conducting oxide has a perovskite structure.

First claim

What is claimed is:

1. A positive electrode active material comprising:
secondary particles, wherein the secondary particles include a plurality of primary particles, the primary particles are a lithium-containing composite metal oxide, inside the secondary particles, an electron conducting oxide is disposed at substantially an entire grain boundary between the primary particles inside the secondary particle, and the electron conducting oxide has a perovskite structure and is represented by Formula (I): ACo x1 M x2 O 3 , wherein in the formula, A is at least one of La and Sr, M is at least one of Mn and Ni, and x1 and x2 satisfy 0<x1≤1, 0≤x2≤1, and 0.6≤x1+x2≤1.

2. The positive electrode active material according to claim 1 , wherein, in Formula (I), x2 satisfies 0.2≤x2≤0.95.

3. The positive electrode active material according to claim 1 , wherein, in Formula (I), A is La.

4. The positive electrode active material according to claim 1 , wherein, in Formula (I), A is Sr.

5. The positive electrode active material according to claim 1 , wherein, in Formula (I), A is both La and Sr.

6. The positive electrode active material according to claim 1 , wherein, in Formula (I), M is Mn.

7. The positive electrode active material according to claim 1 , wherein, in Formula (I), M is Ni.

8. The positive electrode active material according to claim 1 , wherein, in Formula (I), M is both Mn and Ni.

9. A lithium ion secondary battery comprising:
a positive electrode, wherein the positive electrode includes the positive electrode active material according to claim 1 ;
a negative electrode; and
an electrolytic solution.

10. A method of producing the positive electrode active material according to claim 1 , the method comprising:
preparing a precursor using a coprecipitation method;
preparing a mixture by mixing the precursor and a lithium compound;
preparing a sintered product by heating the mixture; and
disintegrating the sintered product to produce the positive electrode active material, wherein the precursor includes the secondary particles, the secondary particles include a plurality of the primary particles inside the secondary particles, and the primary particles are a composite metal hydroxide, and
wherein, when the mixture is heated, the primary particles become the lithium-containing composite metal oxide, and the electron conducting oxide is precipitated at substantially an entire grain boundary between the primary particles.

Assignees

• Toyota Motor Co Ltd
• Sumitomo Metal Mining Co

Inventors

• Sugiura Ryuta
• Kanada Satoshi
• Hayashi Tetsutaro
• Aida Taira

Classifications

• C01G53/82

  Compounds containing nickel, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• H01M10/0525

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

• H01M4/628

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title

• H01M4/624

  Electric conductive fillers · CPC title

• H01M4/525

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