Porous silicon based negative electrode active material, method for manufacturing the same, and rechargeable lithium battery including the same

Patent metadata

Field	Value
Publication number	US-10862116-B2
Application number	US-201715811816-A
Country	US
Kind code	B2
Filing date	Nov 14, 2017
Priority date	Jun 21, 2013
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

The present invention relates to a method of preparing a porous silicon-based negative electrode active material comprising: mixing a porous silica (SiO2) and an aluminum powder; oxidizing all or part of the aluminum powder as an aluminum oxide while at the same time reducing all or part of the porous silica as a porous silicon (Si) by heat-treating a mixture of the porous silica with the aluminum powder, a negative electrode active material, and a rechargeable lithium battery including the same.

First claim

What is claimed is:

1. A method of preparing a porous silicon-based negative electrode active material, comprising:
mixing a porous silica (SiO 2 ) with a first metal powder;
oxidizing all or part of the first metal powder to a first metal oxide as soon as reducing a part of the porous silica as a porous silicon (Si) by heat-treating a mixture of the porous silica with the first metal power;
obtaining a first porous silicon-based material including the porous silicon and the first metal oxide;
mixing a second metal powder which is different from the first metal powder with the obtained first porous silicon-based material;
oxidizing all or part of the second metal powder to a second metal oxide as soon as reducing a remaining porous silica to a porous silicon by heat-treating a mixture of the second metal powder with the first porous silicon-based material; and
obtaining a second porous silicon-based material including the porous silicon, the first metal oxide, and the second metal oxide,
wherein heat-treating the mixture of the porous silica with the first metal powder is performed at a first temperature of 650° C. to 950° C.,
heat-treating the mixture of the second metal powder and the first porous silicon-based material is performed at a second temperature of 650° C. to 950° C.,
the first temperature is higher than a melting point of the first metal powder, and
the second temperature is higher than a melting point of the second metal powder.

2. The method of claim 1 , wherein
the porous silica is obtained from a diatomite.

3. The method of claim 1 , wherein
an average particle size of the porous silica is 100 nm to 50 μm.

4. The method of claim 1 , wherein
an average pore size of a pore of the porous silica is 20 nm to 1 μm.

5. The method of claim 1 , wherein
the first metal powder and the second metal powder are different from each other, and each independently represents aluminum, magnesium, calcium, aluminum silicide (AlSi2), magnesium silicide (Mg2Si), calcium silicide (Ca2Si) or a combination thereof.

6. The method of claim 1 , wherein
anyone of the first metal powder and the second metal powder is aluminum.

7. The method of claim 1 , wherein
average particle sizes of the first metal powder and the second metal powder each independently represents 1 to 100 μm.

8. The method of claim 1 , wherein
the first metal powder is made by adding 25 to 70 weight parts against 100 weight parts of the porous silica.

9. The method of claim 1 , wherein
the first metal powder is made by adding 50 to 80 weight parts against 100 weight parts of the first porous silicon-based material.

10. The method of claim 1 , wherein
the mixing a porous silica with the first metal powder, or
the mixing the second metal powder with the first porous silicon-based material is adding a mineral additive.

11. The method of claim 10 , wherein
the mineral additive is sodium chloride (NaCl), potassium chloride (KCl), calcium chloride (CaCl2)), magnesium chloride (MgCl2) or a combination thereof.

12. The method of claim 1 , wherein,
the mixing a porous silica with the first metal powder, or
the mixing the second metal powder with the first porous silicon-based material is performed by a method for dry mixing.

13. The method of claim 1 , wherein
the first metal oxide and the second metal oxide are different from each other, and each independently represents MgO, CaO, Al2O3, TiO2, Fe2O3, Fe3O4, Co3O4, NiO, SiO2 or a combination thereof.

14. The method of claim 1 , wherein
in the second porous silicon-based material, each of the content of the first metal oxide and the second metal oxide independently represents 1 to 20 weight parts against 100 weight parts of the porous silicon.

15. The method of claim 1 , wherein,
the obtained second porous silicon-based material is a form evenly mixed with the porous silicon, the first metal oxide, and the second metal oxide.

16. The method of claim 1 , wherein,
the obtained second porous silicon-based material includes an alloy of the first metal oxide and the second metal oxide.

17. The method of claim 1 , wherein,
after the heat-treating a mixture of the porous silica with the first metal powder,
further includes removing all or part of the first metal oxide.

18. The method of claim 17 , wherein
the removing all or part of the first metal oxide
is performed by using a solution including hydrochloric acid, phosphoric acid, hydrofluoric acid, sulfuric acid, nitric acid, acetic acid, ammonia water, hydrogen peroxide, or a combination thereof.

19. The method of claim 1 , wherein,
after the heat-treating a mixture of the second metal powder with the first porous silicon-based material,
further includes removing all or part of the second metal oxide.

20. The method of claim 19 , wherein
the removing all or part of the second metal oxide
is performed by using a solution including hydrochloric acid, phosphoric acid, hydrofluoric acid, sulfuric acid, nitric acid, acetic acid, ammonia water, hydrogen peroxide, or a combination thereof.

21. The method of claim 1 , wherein,
after the obtaining the second porous silicon-based material,
further includes carbon coating.

Assignees

• Ulsan Nat Inst Science & Tech Unist
• Sj Mat Co Ltd

Inventors

• Park Soojin
• Choi Sin Ho
• Yoon Ji Hyun
• Bang Byoung Man

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• C01B33/023

  by reduction of silica or {free} silica-containing material · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/36

  Selection of substances as active materials, active masses, active liquids · CPC title

• H01M4/364

  as mixtures · CPC title