Method for manufacturing ultra small particle, positive electrode active material of second battery using the method for manufacturing ultra small particle and method for manufacturing the same, and secondary battery using the positive electrode active material and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-10170764-B2
Application number	US-201113170773-A
Country	US
Kind code	B2
Filing date	Jun 28, 2011
Priority date	Jun 30, 2010
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

An object is to form a positive electrode active material having small and highly uniform particles by a simple process. A template is formed by forming holes in the template by a nanoimprinting method, and the template is filled with a gel-like LiFePO4 material, whereby small-sized LiFePO4 particles are formed and are used as the positive electrode active material of a secondary battery. The particle size can be reduced to less than 50 nm. Further, when the LiFePO4 particles are sintered, the template may be burned down. By making the particle size of the positive electrode active material smaller than the conventional one, a positive electrode that lithium is injected into and extracted from easily can be manufactured.

First claim

What is claimed is:

1. A method for manufacturing a particle comprising:
forming a material film over a substrate;
forming a first protrusion in the material film;
manufacturing a template including a second hole using the material film including the first protrusion; and
filling the second hole in the template with a gel comprising a first material and a second material, whereby a particle is formed in the second hole;
separating the particle from the template by heating,
wherein a diameter of the particle is greater than or equal to 10 nm and less than or equal to 50 nm.

2. The method for manufacturing the particle according to claim 1 , wherein the first protrusion in the material film is formed by a nanoimprinting method.

3. The method for manufacturing the particle according to claim 1 , wherein the second hole in the template is greater than or equal to 10 nm and less than or equal to 50 nm.

4. The method for manufacturing the particle according to claim 1 , wherein the first protrusion in the material film is formed so that the substrate is not exposed.

5. The method for manufacturing the particle according to claim 1 , wherein the template including the second hole is manufactured by exposing the material film with oxygen plasma.

6. The method for manufacturing the particle according to claim 1 ,
wherein the template including the second hole is manufactured by forming a film over the material film and performing a lift-off process to the film, and
wherein the film comprises one selected from the group consisting of aluminum, tungsten, and molybdenum.

7. The method for manufacturing the particle according to claim 1 , wherein the template including the second hole is manufactured by processing the substrate using the material film as a mask.

8. A method for manufacturing a particle comprising:
forming a material film over a substrate;
forming a first protrusion in the material film;
manufacturing a template including a second hole using the material film including the first protrusion;
filling the second hole in the template with a gel comprising a first material and a second material;
heating the gel filled in the second hole in the template, whereby only one particle is formed in the second hole; and
separating the particle from the template by heating,
wherein the first material reacts with the second material by heating the gel.

9. The method for manufacturing the particle according to claim 8 , wherein the first protrusion in the material film is formed by a nanoimprinting method.

10. The method for manufacturing the particle according to claim 8 , wherein the second hole in the template is greater than or equal to 10 nm and less than or equal to 50 nm.

11. The method for manufacturing the particle according to claim 8 , wherein the first protrusion in the material film is formed so that the substrate is not exposed.

12. The method for manufacturing the particle according to claim 8 , wherein the template including the second hole is manufactured by exposing the material film with oxygen plasma.

13. The method for manufacturing the particle according to claim 8 ,
wherein the template including the second hole is manufactured by forming a film over the material film and performing a lift-off process to the film, and
wherein the film comprises one selected from the group consisting of aluminum, tungsten, and molybdenum.

14. The method for manufacturing the particle according to claim 8 , wherein the template including the second hole is manufactured by processing the substrate using the material film as a mask.

15. The method for manufacturing the particle according to claim 8 , wherein the template is eliminated by the heating in the step of separating the particle.

16. The method for manufacturing the particle according to claim 8 , wherein a carbon film is formed over a surface of the particle by using the template as a carbon supply source in the heating of the step of separating the particle.

17. A method for manufacturing a particle comprising:
forming a material film over a substrate;
forming a first protrusion in the material film;
manufacturing a template including a second hole using the material film including the first protrusion;
filling the second hole in the template with a gel comprising a first material and a second material to obtain a particle comprising LiFePO 4 from the second hole; and
separating the particle from the template by heating,
wherein a diameter of the particle is greater than or equal to 10 nm and less than or equal to 50 nm.

18. The method for manufacturing the particle according to claim 17 , wherein the first protrusion in the material film is formed by a nanoimprinting method.

19. The method for manufacturing the particle according to claim 17 , wherein the second hole in the template is greater than or equal to 10 nm and less than or equal to 50 nm.

20. The method for manufacturing the particle according to claim 17 , wherein the first protrusion in the material film is formed so that the substrate is not exposed.

21. The method for manufacturing the particle according to claim 17 , wherein the template including the second hole is manufactured by exposing the material film with oxygen plasma.

22. The method for manufacturing the particle according to claim 17 ,
wherein the template including the second hole is manufactured by forming a film over the material film and performing a lift-off process to the film, and
wherein the film comprises one selected from the group consisting of aluminum, tungsten, and molybdenum.

23. The method for manufacturing the particle according to claim 17 , wherein the template including the second hole is manufactured by processing the substrate using the material film as a mask.

24. The method for manufacturing the particle according to claim 17 , wherein the material film is formed using PMMA.

25. A method for manufacturing a particle comprising:
forming a material film over a substrate;
forming a first protrusion in the material film;
manufacturing a template including a second hole using the material film including the first protrusion;
filling the second hole in the template with a gel comprising a first material and a second material;
heating the gel filled in the second hole in the template to cause a reaction of the first material and the second material, whereby only one particle comprising LiFePO 4 is formed in the second hole, and
separating the particle from the template by heating.

26. The method for manufacturing the particle according to claim 25 , wherein the first protrusion in the material film is formed by a nanoimprinting method.

27. The method for manufacturing the particle according to claim 25 , wherein the second hole in the template is greater than or equal to 10 nm and less than or equal to 50 nm.

28. The method for manufacturing the particle according to claim 25 , wherein the first protrusion in the material film is formed so that the substrate is not exposed.

29. The method for manufacturing the particle according to claim 25 , wherein the template including the second hole is manufactured by exposing the material film with oxygen plasma.

30. The method for manufacturing the particle according to claim 25 ,
wherein the template including the second hole is manuf

Assignees

• Nara Koji
• Mikami Mayumi
• Semiconductor Energy Lab

Inventors

• Nara Koji
• Mikami Mayumi

Classifications

• B29C33/3878

  used as masters for making successive impressions · CPC title

• H01M4/5825 Primary

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

• H01M4/624

  Electric conductive fillers · CPC title

• H01M10/052

  Li-accumulators · CPC title

• B29C33/424

  Moulding surfaces provided with means for marking or patterning (for injection moulding B29C45/372) · CPC title