Lithium ion secondary battery and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-9673451-B2
Application number	US-201615368993-A
Country	US
Kind code	B2
Filing date	Dec 5, 2016
Priority date	Mar 18, 2011
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A lithium ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer over the positive electrode current collector. The positive electrode active material layer includes a plurality of lithium-containing composite oxides each of which is expressed by LiMPO 4 (M is one or more of Fe (II), Mn (II), Co (II), and Ni (II)) that is a general formula. The lithium-containing composite oxide is a flat single crystal particle in which the length in the b-axis direction is shorter than each of the lengths in the a-axis direction and the c-axis direction. The lithium-containing composite oxide is provided over the positive electrode current collector so that the b-axis of the single crystal particle intersects with the surface of the positive electrode current collector.

First claim

What is claimed is:

1. A material comprising single crystal particles of a lithium-containing composite oxide,
wherein the lithium-containing composite oxide is expressed by LiMPO 4 (M is one or more of Fe (II), Mn (II), Co (II), and Ni (II)) that is a general formula,
wherein each of the single crystal particles is a flat single crystal particle,
wherein in each of the single crystal particles, a length in a b-axis direction is shorter than each of lengths in an a-axis direction and a c-axis direction, and a b-plane has a square shape or a substantially square shape,
wherein a ratio of lengths of the single crystal particles in the a-axis direction and the c-axis direction is greater than or equal to 0.8 and less than or equal to 1.2.

2. The material according to claim 1 ,
wherein each length in the b-axis direction of the single crystal particles is greater than or equal to 5 nm and less than or equal to 50 nm.

3. The material according to claim 1 ,
wherein the lithium-containing composite oxide has an olivine structure.

4. The material according to claim 1 ,
wherein the single crystal particles are provided on a substrate so that b-axis of most of the single crystal particles intersect with a surface of the substrate at an angle greater than 60 degrees and less than or equal to 90 degrees.

5. The material according to claim 1 ,
wherein each of the single crystal particles is provided over a substrate so that a b-axis of each of the single crystal particles intersects with a surface of the substrate.

6. The material according to claim 1 ,
wherein the material constitutes an active material of a battery.

7. A material comprising single crystal particles of a lithium-containing composite oxide,
wherein the lithium-containing composite oxide belongs to a space group Pnma (62),
wherein each of the single crystal particles is a flat single crystal particle,
wherein in each of the single crystal particles, a length in a b-axis direction is shorter than each of lengths in an a-axis direction and a c-axis direction, and a b-plane has a square shape or a substantially square shape,
wherein a ratio of lengths of the single crystal particles in the a-axis direction and the c-axis direction is greater than or equal to 0.8 and less than or equal to 1.2.

8. The material according to claim 7 ,
wherein each length in the b-axis direction of the single crystal particles is greater than or equal to 5 nm and less than or equal to 50 nm.

9. The material according to claim 7 ,
wherein the lithium-containing composite oxide has an olivine structure.

10. The material according to claim 7 ,
wherein the single crystal particles are provided on a substrate so that b-axis of most of the single crystal particles intersect with a surface of the substrate at an angle greater than 60 degrees and less than or equal to 90 degrees.

11. The material according to claim 7 ,
wherein each of the single crystal particles is provided over a substrate so that a b-axis of each of the single crystal particles intersects with a surface of the substrate.

12. The material according to claim 7 ,
wherein the material constitutes an active material of a battery.

Assignees

• Semiconductor Energy Lab

Inventors

• Futamura Tomoya
• Moriwaka Tamae
• Kawakami Takahiro
• Momo Junpei
• Inoue Nobuhiro

Classifications

• 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

• H01M4/5825 Primary

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/139

  Processes of manufacture · CPC title