Lithium ion secondary battery and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-11335945-B2
Application number	US-202016791328-A
Country	US
Kind code	B2
Filing date	Feb 14, 2020
Priority date	Mar 18, 2011
Publication date	May 17, 2022
Grant date	May 17, 2022

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 LiMPO4 (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 method for manufacturing a lithium ion secondary battery, comprising the steps of:
forming a plurality of particles comprising a lithium-containing composite oxide;
applying a slurry comprising the plurality of particles to an upper surface of a positive electrode current collector;
exerting pressure on the slurry so that a b-axis of each of the plurality of particles intersects with the upper surface of the positive electrode current collector; and
heating the slurry after exerting pressure on the slurry,
wherein in each of the plurality of 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
wherein a ratio of lengths of each of the plurality of 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 method for manufacturing a lithium ion secondary battery, according to claim 1 , wherein the plurality of particles is formed by a hydrothermal method.

3. The method for manufacturing a lithium ion secondary battery, according to claim 1 , wherein each of the plurality of particles is a single crystal particle.

4. The method for manufacturing a lithium ion secondary battery, according to claim 1 , wherein each length in the b-axis direction of the plurality of particles is greater than or equal to 5 nm and less than or equal to 50 nm.

5. The method for manufacturing a lithium ion secondary battery, according to claim 1 , wherein the b-axis of each of the plurality of particles intersects with the upper surface of the positive electrode current collector at an angle greater than or equal to 60 degrees and less than or equal to 90 degrees.

6. The method for manufacturing a lithium ion secondary battery, according to claim 1 , wherein at least one of the plurality of particles is overlapped with at least another one of the plurality of particles.

7. The method for manufacturing a lithium ion secondary battery, according to claim 1 , wherein the lithium-containing composite oxide has an olivine structure.

8. The method for manufacturing a lithium ion secondary battery, according to claim 1 , 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)).

9. The method for manufacturing a lithium ion secondary battery, according to claim 1 ,
wherein, in each of the plurality of particles, a b-plane has a square shape or a substantially square shape.

10. A method for manufacturing a lithium ion secondary battery, comprising the steps of:
forming a plurality of particles comprising a lithium-containing composite oxide;
applying a slurry comprising the plurality of particles to an upper surface of a positive electrode current collector;
transmitting vibration to the slurry so that a b-axis of each of the plurality of particles intersects with the upper surface of the positive electrode current collector; and
heating the slurry after transmitting vibration to the slurry,
wherein in each of the plurality of 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
wherein a ratio of lengths of each of the plurality of 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.

11. The method for manufacturing a lithium ion secondary battery, according to claim 10 , wherein the plurality of particles is formed by a hydrothermal method.

12. The method for manufacturing a lithium ion secondary battery, according to claim 10 , wherein each of the plurality of particles is a single crystal particle.

13. The method for manufacturing a lithium ion secondary battery, according to claim 10 , wherein each length in the b-axis direction of the plurality of particles is greater than or equal to 5 nm and less than or equal to 50 nm.

14. The method for manufacturing a lithium ion secondary battery, according to claim 10 , wherein the b-axis of each of the plurality of particles intersects with the upper surface of the positive electrode current collector at an angle greater than or equal to 60 degrees and less than or equal to 90 degrees.

15. The method for manufacturing a lithium ion secondary battery, according to claim 10 , wherein at least one of the plurality of particles is overlapped with at least another one of the plurality of particles.

16. The method for manufacturing a lithium ion secondary battery, according to claim 10 , wherein the lithium-containing composite oxide has an olivine structure.

17. The method for manufacturing a lithium ion secondary battery, according to claim 10 , 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)).

18. The method for manufacturing a lithium ion secondary battery, according to claim 10 ,
wherein, in each of the plurality of particles, a b-plane has a square shape or a substantially square shape.

Assignees

• Semiconductor Energy Lab

Inventors

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

Classifications

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M10/0525 Primary

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

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/5825

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